Fluidmaster 5403 Universal Toilet Flapper 3 Inch
- Outlet Connection Size: 3 inches
- Inlet Connection Size: 3 inches
- Thread Size: 3 inches
- Valve Type: Standard
Last refreshed Sep 8, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
A solid pick for a 3-inch valve toilet with a degraded stock flapper, given the silicone seal's longer rated life over standard rubber.
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ASIN: B002C1AVV8Model: 5403Category: Toilet Flappers
Overview
A universal 3-inch toilet flapper with a silicone seal, adjustable flush-volume dial and kink-free chain, built for 1.28 to 1.6 GPF high-efficiency toilets. Not designed to fit 2-inch flush valves.
The silicone seal is the upgrade over Fluidmaster's standard rubber flappers, rated in the listing to last up to 10 times longer, and it pairs with the adjustable dial to fine-tune flush volume specifically on 3-inch valve toilets.
- 3-inch universal flapper
- Silicone seal rated up to 10x longer life
- Adjustable flush-volume dial
- 10-year warranty
Who it's for
Owners of a 3-inch flush valve toilet in the 1.28 to 1.6 GPF range wanting a longer-lasting seal. Owners of 2-inch valve toilets should look elsewhere, such as Fluidmaster's 502P21.
Pros and cons
- Silicone seal rated to outlast standard rubber
- Adjustable dial for flush volume
- 3-inch valve only, not compatible with 2-inch valves
- Limited to the higher-efficiency 1.28 to 1.6 GPF range
Performance notes
Silicone resists the chlorine and hard-water breakdown that shortens the life of standard rubber flappers, and the kink-free chain is meant to keep tension consistent so the flapper seats fully between flushes. The dial adjusts flush volume within the 1.28 to 1.6 GPF range.
Specifications
| Brand | Fluidmaster |
|---|---|
| Model | 5403 |
| Dimensions & fit | |
| Outlet Connection Size | 3 inches |
| Inlet Connection Size | 3 inches |
| Thread Size | 3 inches |
| Size | 3 Inches |
| Item Dimensions | 5.2 × 9 × 3.2 inches |
| Construction & materials | |
| Material Type | Rubber |
| Exterior Finish | Red |
| Included components | |
| Number Of Pieces | 1 |
| Number Of Packs | 1 |
| Unit Count | 1 |
| Included Components | Fluidmaster 5403 3-Inch Universal Water Saving Long Life Toilet Flapper |
| Warranty & support | |
| Manufacturer Warranty Description | Lifetime |
| Other details | |
| Valve Type | Standard |
| Outlet Connection Type | 3-inch Flush Valve |
| Inlet Connection Type | 3-inch Flush Valve |
| Number Of Ports | 2 |
| Connector Type | Socket |
| Thread Type | 3 Inches |
| Number Of Items | 1 |
| Item Type Name | Fluidmaster 5403 3-Inch Universal Water Saving Long Life Toilet Flapper |
| Item Highlight | Silicone seal lasts up to 10X longer, Adjustable dial saves water, Kink-free chain, Resists chlorine and hard water |
| Set Name | Toilet Valve Set |
Frequently asked questions
Will this fit a 2-inch flush valve?
No, per the listing it's not designed to fit 2-inch flush valve toilets.
What makes the silicone seal different?
It's rated to last up to 10 times longer than a regular rubber flapper and resists chlorine and hard water.
Does it have a warranty?
Yes, a 10-year warranty per the listing.