The Korky 3 in universal toilet tank flapper is adjustable to match your original toilet's performance|It has a universal design and will fit oversized 3 in flush valves found in newer 1.6 and 1.28 gpf toilets|The exclusive longest lasting red rubber resists chlorine, bacteria, city water treatment, hard water, and well water|The adjustable flapper has multiple settings to ensure it fits popular 3 in toilet models including: Kohler, TOTO, American Standard, Gerber and Mansfield|Made of flexible rubber for a tight seal and easy to install|Fits 3 in flush valve opening