First of all, I doubt you have spoke to ANYONE at a plumbing supply house. Secondly, call it what you will, but it's a flapper ball that attaches to the overflow tube of the flush valve. Don't EVEN tell me you have contacted two different supply houses and they have no idea what you're referring to....PLEASE....If they're that dense be specific and ask for a Fluidmaster #500 Bulls-Eye-Flapper. If they don't know what that is, your in a paint store.