500 universal toilet flapper. Pre-1994 full flush flapper. The 500-toilet flapper has a rigid frame that ensures a consistent seal every single flush.
FLUIDMASTER solid Frame flapper black
Model - 500P21
This is manufactured in Mexico
Fixes most common cause of a running toilet
Rigid frame aligns flapper properly on every flush
Micro ban prevents growth of harmful microbes
Fits pre-1994 toilets