1.PREMIUM RUBBER --- Rubber toilet stopper flapper, corrosion-resistant resists chlorine, apply to city water, hard & well water. The toilet plug has a stainless steel chain, which can be easily adjusted to a suitable height. 2.COMPATIBILITY --- Toilet flapper for most 3-Inch 2021BP Toto Toilet Stopper Flapper, compatible with TOTO G-Max, THU499S, THU331S, THU175S & 2021BP Models. NOT compatible with TOTO Power Gravity Toilet Models: CST43SD, CST744SD, CST44SLD, CST743SDB, CST744SDB, and CST744SLDB. This Is an Efficient Toilet Repair Part. 3.HOW TO USE --- This is a universal toilet flapper for 3 inch toilet. Make sure you measure the opening in your toilet tank is 3'. Meassure the correct size to advid leaky problem. Tool- install in 3 minutes. Pulled out the old flapper, put this one on. 4.WATER-SAVING --- Toilet drain plugs adopt an integrated design with high manufacturing precision. replace the leaky and old toilet flapper, save on expensive water waste. High quality long lasting rubber flapper reduce maintenance cost and superior performance.