The Fluidmaster 506 Universal Toilet Flapper is designed to be a simple and easy to install replacement toilet flapper. Featuring a flexible design this flapper can be used on flush valves with, or without mounting ears. A universal fit with most brands, and most 2'' brass, or plastic flush valves. Quickly replace an outdated or leaky flapper. For best use in older 3.5 GPF toilets, this flapper offers fast installation combined with a universal fit, to make solving common flapper problems easie