The 3" universal flapper restores the original performance of all major brands and models of 3" toilets, including Toto , Kohler , Eljer, American Standard, Gerber , and Mansfield. With 2 simple adjustments, it will fit all current and future 3" flapper style toilets. Instructions are on the inside of the packaging to provide flapper settings for every available 3" toilet on the market. No trial and error testing is needed. Highly durable, chlorine-resistant materials.