1.Applicable Models: 3 inch toilet flapper compatible with most standard flush valves and toilet models, including 20-900, 20-902, 20-904, 20-910, 20-912, 21-018, 21-011, 28-180, 28-183, 28-530, 28-535,28-980, 28-990, 28-992, 28-994, 28-995, 28-970. Will also work in tank models 28-890/2/5, but not all model variants of the 28-890/2/5 used the same flapper 2. Replacement Toilet Parts: Fitting Flapper for 3-inch Flush Valves, The 3' universal flapper to fit flush valves in most toilets and the flexible long lasting rubber creates a tight seal 3.Easy to Install: No tools are required for installation. Includes stainless steel chain with clip hook. You will install it easily with confidence. Please make sure to check the size before placing the order 4.Long Lasting: The toilet flapper replacement is built with soft, long lasting rubber to ensure the practicability and prolong life span.The hook and chain is made of solid stainless steel.High quality rubber flapper stops leaking and running toilets