
Korky 2011BP
Score: 72/100
Fluidmaster PerforMAX Flapper
Score: 88/100Rankings

The Fluidmaster 502P21 PerforMAX is a universal, adjustable 2-inch toilet flapper designed to resolve weak flushes, running toilets, and water waste in toilets with 1.28, 1.6, or 3.5+ GPF ratings. It features a dial-adjustable mechanism for customizing flush volume, Microban antimicrobial protection, and a solid frame to prevent twisting during operation. It is best suited for homeowners with most 2-inch flush valve toilets experiencing weak flushes, running toilets, double flushes, or high water use.

The Korky 2011BP is a replacement hinge-style flapper designed specifically for Kohler one-piece toilets, replacing OEM parts #84995 and #1000490. Constructed from flexible rubber with stainless steel components, it features a red finish and is engineered to resist chlorine damage for extended lifespan. It is best suited for owners of Kohler one-piece toilets requiring a durable, chlorine-resistant replacement flapper that matches OEM performance.
| Attribute | ![]() | ![]() |
|---|---|---|
2 inchesbest | 2 inchesbest | |
1 countbest | 1 countbest |
Click an attribute name to sort · Green = best, red = worst (relative to this comparison)
| Attribute | ![]() | ![]() |
|---|---|---|
Material & Durability(1) | ||
Material | Rubber/Stainless Steel | Rubber/Plastic |
Design & Features(3) | ||
Chain Material | Stainless Steel | Standard |
Installation Type | Hinge | DIY |
Flapper Type | Hinge | Adjustable Flapper |
Packaging & Support(1) | ||
Warranty Period | Standard | 5 Years |
Compatibility & Fit(4) | ||
Flush Valve Compatibility | Kohler One-Piece | Universal |
Universal Fit | false | true |
Toilet Type Compatibility | One-Piece | Standard |
Flush Valve Size | 2 inches | 2 |

Products in the top-left offer the best value (high score, low price).

Professional reviewers, including Home Improvement Expert Bob Vila, rate the Fluidmaster 502P21 as the best overall 2-inch flapper for addressing running toilets. It is praised for its ability to fix weak flushes, double flushes, and water waste. Manufacturer sources describe it as the 'gold standard' and 'high performance standard' due to its durability, adjustability, and Microban protection.
Search results do not provide direct consumer quotes or aggregated star ratings. However, implied praise from product pages suggests users value the reliable sealing, water savings, and ease of use for fixing running toilets. No recurring complaints are detailed in the available data.

