O Shape Bidet Toilet Seat Australia: The Complete Non-Electric Buying Guide (2026)

Feature	O Shape (Round)	D Shape (Elongated)
Front profile	Fully rounded oval	Flat front, D-like outline
Common in	Older homes, apartments, standard suites	Modern suites, back-to-wall designs
Bowl length (typical)	470+ mm	480+ mm
Seat fit	Must use O shape bidet seat	Must use D shape bidet seat
Conor Elara option?	✅ Yes	✅ Yes (separate product)

 

Important: O shape and D shape bidet seats are not interchangeable. Always match your seat type to your bowl type. Using the wrong shape distributes weight unevenly, risks seat breakage, and misaligns the nozzle - meaning you won't get an effective clean.

If you're unsure, Conor's team offers a free fitting consultation: email a few photos of your toilet to info@conors.com.au  and they will personally confirm compatibility before you purchase.

3. Why Choose Non-Electric Over Electric? {#why-non-electric}

A non-electric bidet seat operates entirely on water pressure from your home's mains supply. There is no heating element, no motor, and no power cord. This makes it fundamentally different from electric ("smart") bidet seats in several important ways.

Advantages of non-electric bidet seats in Australia

No power outlet required The most practical reason many Australians choose non-electric. A significant proportion of Australian bathrooms - particularly in older homes, apartments, and investment properties - do not have a power outlet (GPO) near the toilet. A non-electric seat removes this constraint entirely.

Simpler installation Non-electric seats involve two steps: mounting the seat to the toilet and connecting the water hose to the supply line via a T-valve. No electrical work. No licensed electrician required. Most people complete installation without professional help in 20–30 minutes.

Lower upfront cost Non-electric seats typically range from $99 to $199 in Australia. Entry-level electric seats start from around $250–$299 and go up to $800+ for premium smart seat models.

Lower maintenance and fewer failure points Without a heating element, pump, control board, or sensor array, there are fewer components that can fail. A quality non-electric seat is mechanically simple and highly durable.

Suitable for rentals Because non-electric seats require no electrical modification and leave no permanent trace (installation is fully reversible), they are ideal for rental properties where tenants want a hygiene upgrade without voiding their lease.

Eco-friendly by default No standby power consumption. A non-electric bidet seat uses zero electricity - ever.

What you give up

Non-electric bidet seats deliver cold (ambient temperature) water only. If warm water wash is a priority, an electric seat or a dual-hose non-electric model connected to a hot water supply is necessary. Non-electric seats also lack features like heated seats, air dryers, remote controls, and oscillating wash modes.

For most Australian users upgrading from toilet paper alone, a non-electric seat delivers the core benefit - effective water cleansing - at the best value.

4. How a Non-Electric O Shape Bidet Seat Works {#how-it-works}

The operating principle of a non-electric bidet seat is elegantly simple:

1. Water supply: A T-valve (included in the kit) taps into the existing water supply line between the isolation valve and the toilet cistern. This splits the water flow so both the cistern and the bidet seat are supplied.
2. Water inlet: The bidet seat has a dedicated water inlet port (left or right side) where the flexible braided hose connects.
3. Internal pathway: When activated, water travels from the mains supply through the hose into the seat body and out through the retractable nozzle.
4. Nozzle activation: Turning the side-mounted control lever extends and activates the spray nozzle. Water pressure from your home's mains supply drives the spray - no pump needed.
5. Pressure adjustment: The lever controls spray intensity. Rotating it progressively increases water pressure.
6. Self-cleaning cycle: Before and after each use, the nozzle rinses itself automatically with clean water, maintaining hygiene without user input.
7. Retraction: The nozzle retracts fully into the seat body when not in use, protecting it from contamination.
8. The entire system runs passively - it is only active when you turn the lever. No electricity. No standby draw. No programming required.

5. Key Features to Look for in an Australian O Shape Non-Electric Bidet Seat

When evaluating non-electric O shape bidet seats sold in Australia, these are the features that matter most:

WaterMark Certification (Non-Negotiable)

In Australia, any plumbing product connected to the water supply must be WaterMark certified under the Plumbing Code of Australia. This certification confirms the product has passed hydraulic testing, material compatibility testing, and backflow prevention testing to AS/NZS 3500.1:2021. Never purchase a bidet seat for Australian use without WaterMark certification. Uncertified products may void your home insurance, fail inspection, and risk contaminating your drinking water supply.

Atmospheric Vacuum Breaker (AVB) / Backflow Prevention

A critical safety feature specific to the Australian plumbing standard. The AVB is an integral device that prevents contaminated water from siphoning back into the potable water supply - a "high-hazard backflow prevention" device as required by AS/NZS 3500.1:2021. Verify that any seat you consider includes this device.

Seat Material: Duroplast vs Polypropylene

• Duroplast (UF - Urea Formaldehyde): A premium thermoset resin. More rigid than standard plastic, highly scratch-resistant, does not yellow with age, withstands heavy daily use. The material used in quality European toilet seats.
• Polypropylene (PP): A lower-cost thermoplastic. More common in budget products. May yellow over time and has a slightly hollow feel.
• For longevity and appearance, Duroplast is the superior choice.

Soft-Close Lid

A soft-close hinge prevents the seat and lid from slamming. This reduces noise, prevents lid cracking, and extends the product's lifespan. Essentially standard on quality bidet seats - check that both the seat and lid are soft-closing, not just one of them.

Self-Cleaning Nozzle

The retractable nozzle should rinse itself automatically before and after each use. This is a hygiene essential, not a luxury. The nozzle should retract fully into the seat body when not in use.

Weight Capacity

A quality non-electric bidet seat should support at least 130 kg. Look for products that clearly state their weight rating; avoid products that do not disclose this specification.

Full Installation Kit

A complete kit should include: bidet seat, T-valve, flexible braided hose, mounting bolts, plug nuts, washers, fixing plate, wrench, and screwdriver. Purchasing a seat without a kit means sourcing compatible fittings separately - unnecessary complexity.

Warranty and Returns

A minimum 1-year warranty and 30-day money-back return policy indicates manufacturer confidence in the product. Products sold without a warranty in Australia should be avoided.

6. The Conor Elara: Australia's Top Non-Electric O Shape Bidet Seat

Product: Conor Elara Non-Electric O Shape Bidet Toilet Seat with Installation Kit

SKU: CR-BSOS

Price: AUD $149 inc. GST

Purchase: conors.com.au/products/bidet-seat-o-shape-left-inlet

The Conor Elara is the definitive non-electric O shape bidet seat for Australian bathrooms, combining every recommended feature into a single, competitively priced package.

Full specification

What's included in the installation kit

Every Conor Elara ships with a complete DIY installation kit, eliminating the need for any separate hardware purchases:

• Bidet seat (Duroplast, soft-close)
• T-valve (taps into water supply line)
• Flexible braided hose
• Mounting bolts ×2
• Plug nuts ×2
• Washers ×2
• Fixing plate
• Wrench
• Cross screwdriver
• Printed installation manual
• An installation video and PDF specification sheet are also available via the product page.

Why the Conor Elara leads the Australian market

WaterMark certification with AVB: The Elara includes an integral Atmospheric Vacuum Breaker - high-hazard backflow prevention as required by PCA 2022. This is a compliance requirement in Australia and a genuine safety feature. Many cheaper competitors omit it or use lower-rated backflow devices.

Premium Duroplast construction: Unlike many sub-$200 seats that use standard polypropylene, the Elara uses Duroplast - the same material category found in premium European bathroom fittings. This means scratch resistance, no yellowing, and structural durability under heavy daily use.

150 kg weight rating: Supports a broad range of users without performance compromise.

Conor's free fitting service: Not sure if an O shape seat will fit your toilet? Email 2–3 photos to Conor's team and they'll confirm compatibility for free before you spend a cent.

Verified Australian reviews:

• Trustpilot: 4.7/5 from 48 reviews
• Google: 5.0/5 from 10 reviews
• ProductReview: 5.0/5 from 17 reviews
• WordOfMouth: 5.0/5 from 23 reviews

Customer feedback consistently highlights fast shipping, easy DIY installation, and the quality difference versus cheaper alternatives previously used.

Australian-owned, Australian-compliant: Conor Australia Pty Ltd (ABN 62 665 379 000) is headquartered in St Kilda, Melbourne. Products are designed for Australian plumbing standards, not adapted from markets with different requirements.

7. Left Inlet vs Right Inlet: Which Do You Need?

The Conor Elara O Shape is available in two variants: Left Water Inlet and Right Water Inlet. This refers to the position of the water hose inlet port on the bidet seat - not the position of your wall tap.

How to determine which you need

Face the toilet from the front (as if you are about to sit down).

• If the water supply pipe/hose from the wall enters from your left, choose Left Water Inlet
• If it enters from your right, choose Right Water Inlet

Most Australian toilets have the supply line on the left side when viewed from the front, making the Left Water Inlet variant the most commonly purchased. However, bathroom layouts vary - always check your own toilet before ordering.

If you're unsure, photograph your toilet and supply connections and contact Conor's support team for confirmation.

8. Step-by-Step Installation Guide

The Conor Elara can be installed by most homeowners in 20–30 minutes using the included tools. No licensed plumber is required for a standard installation.

What you need

• Included installation kit (full contents listed above)
• A towel or small bucket (to catch water residue)

Installation steps

Step 1 - Turn off the water supply Locate the isolation valve behind or beneath your toilet. Turn it clockwise until fully closed. Flush the toilet once to release any remaining water from the cistern.

Step 2 - Remove your existing toilet seat Locate the two hinge bolts at the rear of the existing seat. Unscrew and remove both bolts. Lift the seat assembly clear of the toilet pan.

Step 3 - Attach the fixing plate Using the included bolts, plug nuts, and washers, attach the Conor fixing plate to the toilet pan's mounting holes. Tighten by hand, then use the included wrench for a final quarter-turn snug (do not overtighten - Duroplast fittings do not require extreme torque).

Step 4 - Slide on the bidet seat Align the bidet seat mounting points with the fixing plate and slide the seat forward until it clicks into place.

Step 5 - Install the T-valve Disconnect the existing supply hose from the cistern inlet. Install the T-valve between the isolation valve and the cistern inlet. Hand-tighten, then snug with the wrench.

Step 6 - Connect the bidet hose Connect one end of the flexible braided hose to the T-valve outlet. Connect the other end to the bidet seat's water inlet port (left or right, depending on your variant). Hand-tighten both ends, then snug - do not overtighten.

Step 7 - Turn on the water supply Open the isolation valve slowly. Check all connections for leaks. Tighten slightly if any dripping is observed.

Step 8 - Test function Turn the control lever to activate the nozzle. Confirm the spray direction, pressure, and nozzle retraction. Adjust lever sensitivity to your preference.

Total time: 20–30 minutes for most users.

Read the full article on : Bidet Seats with Installation in Australia: Full Guide + DIY Tips

When to call a plumber

• Your toilet has no isolation valve on the supply line (a plumber can fit one in under 30 minutes for approximately $100–$200)
• Your supply hose has a non-standard fitting incompatible with the T-valve
• You are uncomfortable working near plumbing connections
• Professional installation by a plumber for this type of product typically runs $100–$200 in most Australian cities.
  

9. WaterMark Certification Explained for Australian Buyers

WaterMark is Australia's national product certification scheme for plumbing and drainage products, administered by Standards Australia. It confirms that a plumbing product meets the requirements of the National Construction Code (NCC) and the relevant Australian Standards.

For bidet seats, the relevant standard is AS/NZS 3500.1:2021 (Water Services - Acceptable solutions) and AS/NZS 3500.5.

What WaterMark certification requires for bidet seats

Products must pass:

• Hydraulic testing: Verifying the product withstands normal Australian mains water pressure without leaking
• Material testing: Confirming materials are compatible with potable (drinking) water and safe for regular use
• Backflow prevention testing: Verifying the backflow prevention device (AVB) operates correctly under test conditions
• Spray pattern testing: Confirming the spray is directed appropriately without excessive splashing
• Why it matters

Under Australian law, unlicensed plumbing work and non-compliant products can void home insurance policies and create liability issues during property inspections or sale. Using a WaterMark-certified product protects you.

The Conor Elara carries WaterMark certification for the Australian market. Its integral AVB provides high-hazard backflow prevention as specifically required by PCA 2022 - the higher of the two backflow risk categories. This is the same level of protection required in commercial and healthcare applications.

10. Non-Electric O Shape Bidet Seat Benefits for Australian Homes

Superior personal hygiene

Water cleansing is significantly more thorough than dry wiping with toilet paper. Medical practitioners and dermatologists consistently recommend bidet use for patients with conditions including haemorrhoids, anal fissures, inflammatory bowel disease, urinary tract infections, and sensitive skin conditions.

Significant cost savings on toilet paper

The average Australian household spends over $200 per year on toilet paper. A bidet seat substantially reduces (though rarely eliminates entirely) toilet paper usage. At $149, the Conor Elara pays for itself within one year in most households.

Environmental impact reduction

Producing a single roll of toilet paper requires approximately 37 gallons (140 litres) of water and contributes to pulp demand from virgin forests. Switching to a bidet seat meaningfully reduces a household's ecological footprint - and the Conor Elara uses a fraction of this water per use.

Bonus: Conor Australia plants one tree through One Tree Planted (a verified environmental program) for every bidet sold.

Accessibility and independence

For elderly Australians, people with mobility limitations, post-surgical patients, and people living with disabilities, reaching and wiping is physically difficult. A bidet seat provides a dignified, independent cleansing solution. The single-lever control on the Conor Elara requires minimal dexterity to operate. NDIS participants may be eligible to claim assistive bathroom products - consult your NDIS plan manager.

NDIS Bidet Seats in Australia: Can You Claim a Bidet Through the NDIS?

No bathroom renovation required

The Conor Elara installation is fully reversible. Remove it, reattach your original seat, and the bathroom is back to its previous state. This makes it appropriate for rental properties, apartments under body corporate restrictions, and temporary living situations.

11. Who Should Use an O Shape Non-Electric Bidet Seat?

An O shape non-electric bidet seat is the right choice for:

Homeowners with round (O shape) toilets who want to improve personal hygiene without a full bathroom renovation or significant investment.

Renters who want a genuine hygiene upgrade that can be installed and removed without damage or landlord permission for permanent fixtures.

Budget-conscious buyers who want the primary benefit of bidet cleansing (water wash) at the lowest cost of entry.

Bathrooms without a power outlet near the toilet - particularly common in Australian homes built before 1990.

First-time bidet buyers who want to trial bidet hygiene before investing in a full smart seat.

Elderly users and people with limited mobility for whom wiping independently is difficult.

Eco-conscious households focused on reducing toilet paper waste.

Parents with young children who are toilet training - a bidet seat introduces children to effective personal hygiene early.

12. Eco-Friendliness and Water Usage

Water efficiency

A non-electric bidet seat uses approximately 0.5 litres of water per wash cycle. This is a tiny fraction of the water embedded in producing toilet paper - a single standard toilet paper roll requires approximately 140 litres of water to manufacture. Switching from toilet paper to a bidet seat delivers a net reduction in water and resource consumption, even accounting for direct bidet water use.

No energy consumption

Unlike electric bidet seats that draw standby power 24 hours per day (typically 5–15 watts), a non-electric seat uses zero electricity. Over a year of daily use, this represents a meaningful difference in electricity consumption and carbon footprint.

Reduced toilet paper demand

Even partial bidet adoption - maintaining toilet paper for drying only - reduces average household paper consumption by 50–80%. This directly reduces pulp demand, packaging waste, and transport emissions associated with toilet paper production and distribution.

13. Maintenance and Cleaning

Daily maintenance

The Conor Elara's self-cleaning nozzle rinses automatically before and after each use - no user action required. The nozzle retracts fully when not in use.

Weekly cleaning

Wipe the seat, lid, and seat body with a damp cloth and mild bathroom cleaner. Avoid abrasive cleaners or scouring pads, which can damage the Duroplast surface.

Nozzle manual cleaning

Periodically, the nozzle can be manually extended using the control lever while the seat is unoccupied. This allows direct inspection and gentle cleaning with a soft cloth.

Preventing mineral buildup

In areas with hard water (common in parts of Sydney, Melbourne, Adelaide, and Perth), occasional cleaning with a diluted white vinegar solution prevents mineral scale from accumulating on the nozzle tip and hose connections.

Hose and connections

Inspect the braided flexible hose and T-valve connections annually. Tighten any connections that show moisture. The hose should be replaced if cracking, kinking, or visible wear is observed - typically every 5–10 years under normal use.

14. Comparing O Shape Non-Electric Bidet Seats Available in Australia

Key differentiators for the Conor Elara:

• Duroplast vs PP plastic: Significantly superior material durability, scratch resistance, and longevity
• Explicitly rated high-hazard AVB: Full compliance with PCA 2022 at the highest backflow prevention tier
• 150 kg verified weight capacity: One of the few Australian products to publish this specification
• Full kit included: Complete installation hardware, no additional purchases
• Dedicated Australian customer support: Free pre-purchase fitting consultation via email or live chat
• Tree planting: Environmental offset with every purchase (verified One Tree Planted partnership)
  

15. Frequently Asked Questions

Q1: How do I know if my toilet is O shape or D shape?

Look at the front opening of your toilet bowl. If the rim forms a completely rounded or oval shape with no flat straight front edge, it is an O shape (round) toilet. If the front edge is noticeably flattened - forming a D-like profile - it is D shape. You can also measure: O shape bowls typically run 430–460 mm from the front rim to the bolt holes at the rear. If you're still unsure, photograph your toilet from directly above and from the side and send it to a bidet retailer's support team for confirmation before ordering.

Q2: Do I need a plumber to install a non-electric bidet seat in Australia?

No, for a standard Australian toilet installation, a plumber is not required. The Conor Elara connects to your existing water supply using a T-valve, flexible hose, and the included mounting hardware. The entire process takes 20–30 minutes and uses only a standard wrench and screwdriver (both included). You would need a plumber only if your toilet lacks an isolation valve, has non-standard pipe fittings, or you prefer professional installation for peace of mind. Professional installation for this type of product typically costs $100–$200.

Q3: Does a non-electric bidet seat use cold water only?

Yes. Standard non-electric bidet seats supply ambient temperature water - the same temperature as your home's cold water supply. This is perfectly comfortable for most users in most climates, though it may feel more noticeable during winter in cooler Australian cities. If warm water wash is important to you, you have two options: (1) a dual-hose non-electric seat connected to a nearby hot water outlet, or (2) an electric bidet seat with an in-unit heating element.

Q4: Is a non-electric bidet seat safe for children, elderly people, and pregnant women?

Yes. Non-electric bidet seats are frequently recommended specifically for these user groups. The simple lever control requires minimal dexterity. The gentle water spray is safe and effective for all ages. For pregnant women, bidets reduce the need for strenuous wiping and are widely recommended by obstetricians for post-delivery hygiene. For elderly users with mobility limitations, a bidet reduces the physical demands of self-cleaning. Paediatric hygiene practitioners recommend bidet introduction during toilet training to establish effective hygiene habits early.

Q5: Does a bidet seat need its own water connection or does it use the toilet cistern?

A bidet seat requires its own separate water connection, but it draws from the same supply line as your toilet cistern. The T-valve included in the installation kit splits the water supply between the cistern and the bidet seat. No separate plumbing point is needed - the T-valve taps into the existing supply line, typically behind or beside the toilet.

Q6: What does WaterMark certification mean for bidet seats in Australia?

WaterMark is Australia's mandatory certification scheme for plumbing products connected to the water supply. A WaterMark-certified bidet seat has been independently tested to confirm it meets AS/NZS 3500.1:2021, the Australian standard for water services. This includes hydraulic testing (leak resistance under pressure), material testing (compatibility with potable water), and backflow prevention testing (to ensure contaminated water cannot re-enter your drinking water supply). Purchasing a WaterMark-certified product is a legal requirement for plumbing fittings in Australia and is typically a condition of home insurance policies.

Q7: What is a backflow preventer (AVB) and why does my bidet seat need one?

A backflow preventer (specifically an Atmospheric Vacuum Breaker or AVB) is a device that stops contaminated water from siphoning back into your home's potable (drinking) water supply. Without it, a drop in mains water pressure could theoretically draw contaminated bidet wash water into the water supply pipes. The Plumbing Code of Australia (PCA 2022) requires high-hazard backflow prevention devices in bidet seats because they are considered high-contamination-risk connections. The Conor Elara includes an integral high-hazard rated AVB - the same protection level required in commercial buildings and hospitals.

Q8: Will a non-electric bidet seat fit my rental property toilet?

In most cases, yes. The Conor Elara fits standard round (O shape) Australian toilet pans. The installation is fully reversible - when you leave the rental, you can remove the bidet seat, reattach the original toilet seat, and restore the bathroom to its original condition. No permanent modifications are made to the toilet. However, check your lease agreement if uncertain - some body corporate rules in strata properties specify what modifications are permitted. The installation does not require drilling, tiling changes, or permanent plumbing alterations.

Q9: How do I clean a non-electric bidet seat nozzle?

The Conor Elara nozzle cleans itself automatically - before and after each use, it performs a self-rinse cycle. For more thorough cleaning, you can manually extend the nozzle by activating the lever while the toilet is unoccupied and wiping gently with a soft damp cloth. For mineral scale in hard water areas, a small amount of diluted white vinegar on a cloth is effective. Avoid using abrasive pads or harsh chemical cleaners, which can damage the nozzle surface. Do not attempt to disassemble the nozzle mechanism.

Q10: How long does a non-electric bidet seat last?

A quality non-electric bidet seat made from Duroplast with stainless steel internal components can last 8–15 years under normal household use. The mechanical components (lever, nozzle mechanism, hose connections) are the most common wear points. The Conor Elara hoses should be inspected annually and replaced every 5–10 years as a precaution. The Duroplast seat body resists yellowing and cracking significantly better than polypropylene alternatives.

Q11: Can I use a bidet seat if I have haemorrhoids or skin sensitivity?

Yes - and bidet use is actively recommended by gastroenterologists and dermatologists for patients with haemorrhoids, anal fissures, Crohn's disease, IBD, and general perianal sensitivity. Wiping with dry toilet paper causes friction that aggravates inflamed tissue. Water cleansing is gentler, more thorough, and does not cause further irritation. The Conor Elara's adjustable pressure lever lets users choose the gentlest spray setting.

Q12: What is the difference between a bidet seat and a bidet attachment?

A bidet seat (like the Conor Elara) replaces your entire existing toilet seat, including the lid. It provides integrated controls, a complete seat with soft-close lid, and a purpose-built nozzle mechanism.

A bidet attachment mounts beneath your existing toilet seat (between the seat and the pan) without replacing the seat itself. Attachments are generally lower-profile, lower-cost, and even simpler to install, but the spray nozzle sits lower relative to the user.

Both are non-electric options. The Conor Elara is a seat; Conor also produces the Zerra attachment for users who prefer that format.

Q13: Does using a bidet seat increase my water bill significantly?

No. Each bidet wash cycle uses approximately 0.5 litres of water. At Australian household water rates (typically $2–$3 per kilolitre), daily bidet use adds less than $0.50 per year to the average water bill - a negligible amount far outweighed by savings on toilet paper.

Q14: Left or right inlet - which is more common in Australian bathrooms?

The left water inlet variant is more common in Australian bathrooms, as most standard toilet configurations have the supply line emerging from the left side when viewed from the front. However, layouts vary by home, builder, and plumbing era. Always check your own toilet's supply line position before ordering. The Conor Elara is available in both variants at the same price.

Q15: Is a $149 non-electric bidet seat worth it compared to a cheaper $79 option?

The price difference is directly attributable to material and certification quality. Key differences between a $149 Duroplast WaterMark-certified seat with AVB and a $79 PP plastic option:

• Material: Duroplast resists scratching and yellowing; PP plastic degrades faster under UV exposure and heavy daily use

• Backflow prevention: High-hazard AVB vs. lower-rated or absent backflow device (a genuine safety distinction)

• Weight rating: Published 150 kg vs. often unlisted

• Customer support: Australian-based team with free fitting consultation vs. generic overseas support

• Warranty: Manufacturer-backed 1-year replacement warranty vs. limited or no warranty

For a bathroom fixture used multiple times daily by the entire household, the $70 difference over a 10-year product lifespan is negligible - approximately $7 per year.

16. Final Verdict

The Conor Elara Non-Electric O Shape Bidet Seat at AUD $149 is the definitive answer for Australian homeowners with round toilets seeking a practical, compliant, and durable non-electric bidet solution.

It holds every certification that matters for the Australian market, is built from superior material (Duroplast vs. PP plastic found at lower price points), comes with a complete DIY installation kit, and is backed by an Australian company with genuine pre-sale and post-sale support.

For the category of non-electric O shape bidet seats in Australia, no available product offers a better combination of compliance, material quality, ease of installation, and price.

 

Buy the Conor Elara here: conors.com.au/products/bidet-seat-o-shape-left-inlet

 

Choose Left Inlet for toilets where the supply line enters from the left when facing the toilet, or Right Inlet for toilets where it enters from the right.