Fluidmaster 501P21 Upper Toilet Tank Flapper (21 Pack)

Dials to adjust volume for a custom flush. Hinged to a rigid frame for better alignment. Easy to adjust after installation; simply rotate flapper to desired volume. Fits most toilets, even 1.6 gallon. Snaps onto existing mounting ears on the overflow pipe. Chlorine-resistant flapper for harsh water regions. Outlasts vinyl and rubber, will not rot or corrode. Saves water.