Gerber 99-652 G0099652 takes a 99-647 G0099647 Flapper. This flush valve comes with the seal to seal the flush valve to the tank, and the nut to hold it on. This flush valve fits toilet models 28-790-09, 28-790-15, 28-790-25, 28-794, 28-795, 28-490, 28-492, 28494, 28-790, 21-402, 21-412, and 21-418. The flapper also comes complete with this flush valve.