Please Help with Gasket Replacement!!

[Sameezy]

Does anyone know what size/type of tank to toilet gasket I need for this?

I cannot find the brand/model of the toilet anywhere.

 

[Jeff Handy]

Look inside the tank, on the back.
There should be printing, or a molded in area of info.

Meanwhile, it looks like it needs the typical black spongy gasket, shaped to match the hex nut.

 

[Jeff Handy]

You are asking for disaster balancing your tank on the bowl like that, IMHO.

 

[Jeff Handy]

Bring in the old gasket (or whatever is left of it) to HD or Lowes or a hardware store, easy to visual match.

Sometimes they sell the same gasket in a thick and also a thin version.
Buy both, beats having to go back.

Measure the flush valve opening, is it two inches or three inches?

Post a pic of the inside back of the tank.

 

[CT18]

Look on the under side of the tank lid also.