Fluidmaster s highest performance toilet flapper is the 502 PerforMAX Universal Water-Saving 2-inch Toilet Flapper. Fully adjustable for a customized flush. Simply turn the dial to more water per flush or less depending on your needs. Quickly save water and improve flush performance with this solid frame design. Built to last and featuring a built-in Microban technology. Only Fluidmaster has toilet flappers with built-in Microban protection. Microban is built into the construction of our flappers to fight flapper breakdown and combat bacteria for a long lifespan. Best for newer toilets 1.28 1.6 3.5 GPF or more (before and after 1994). The Fluid master 502 Flappers quickly replaces and upgrades old or corroded 2 in. toilet flappers.