Briggs Flapper Valve

I have an older model Briggs one piece silent flushing toilet. A label in the tank has these numbers on it - 6000, 6002, 6005, 6006, 6011, 6012, 6014. The lid also shows 4300.

Anyway, the flapper valve has turned to sponge. What flapper valve can I use to replace it? Are there any installation challenges?

Thanks.

I'm not familiar with your toilet brand, but Fluidmaster makes good replacement innards for toilets and I'm sure there is a model that would work for you. These are fairly simple replacements.

flapper

Some Briggs need a special flapper since the "arms" that it connects to do not have bends on them to hold a regular Korky style.