Fluidmaster 502P21 PerforMAX Universal Toilet Flapper 2 Inch
- Outlet Connection Size: 2 inches
- Inlet Connection Size: 2 inches
- Valve Type: Flapper
- Outlet Connection Type: Flange
Last refreshed Sep 8, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
A straightforward fix for a running 2-inch-valve toilet, with a dial that lets you adjust flush volume instead of settling for whatever the old flapper gave you.
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ASIN: B000BVS3H0Model: 502P21Category: Toilet Flappers
Overview
A replacement toilet flapper built for 2-inch flush valves, with an adjustable dial to tune flush volume and a solid frame treated with Microban to resist corrosion. Covers high-efficiency toilets from 1.28 to 3.5 gallons per flush.
This is a repair part, not a fixture: it's meant to replace a worn or warped flapper that's causing ghost flushing or a running toilet. The dial lets you adjust flush volume after install rather than being locked to one fixed setting.
- Fits 2-inch flush valves
- Adjustable dial for flush volume
- Microban corrosion-resistant frame
- 5-year warranty
Who it's for
For owners of a 2-inch flush valve toilet, which covers most standard 1.28 to 3.5 GPF models, dealing with a running toilet or wanting to tune flush volume. Not a match for 3-inch valve toilets.
Pros and cons
- Adjustable dial for flush volume
- Microban material resists corrosion and chlorine
- Listed install time around 10 minutes
- Fits 2-inch valves only, not 3-inch
- One color and style option
Performance notes
The solid frame is meant to keep the flapper aligned over the valve seat on every flush instead of twisting or drifting the way looser flappers can, and the Microban-treated material is aimed at resisting the bacteria and mineral buildup that break rubber flappers down over time.
Specifications
| Brand | Fluidmaster |
|---|---|
| Model | 502P21 |
| Dimensions & fit | |
| Outlet Connection Size | 2 inches |
| Inlet Connection Size | 2 inches |
| Item Weight | 0.05 pounds |
| Size | 1 Pack |
| Item Dimensions | 4.9 × 3.5 × 3.5 inches |
| Construction & materials | |
| Material Type | Rubber |
| Exterior Finish | Metal |
| Included components | |
| Number Of Pieces | 1 |
| Number Of Packs | 1 |
| Unit Count | 1 |
| Included Components | Product Only |
| Warranty & support | |
| Manufacturer Warranty Description | 5 Year Warranty |
| Other details | |
| Valve Type | Flapper |
| Outlet Connection Type | Flange |
| Inlet Connection Type | Barb |
| Connector Type | Mechanical |
| Number Of Items | 1 |
| Item Type Name | Toilet Replacement-Parts |
Frequently asked questions
What flush valve size does the 502P21 fit?
2-inch flush valves, which covers most 1.28 to 3.5 gallon-per-flush toilets.
Will this stop a running toilet?
It's built to replace a leaky or corroded flapper, a common cause of ghost flushing and running toilets.
Is there a warranty?
Yes, a 5-year warranty per the listing.