【Compatible Models】 Compatible with TOTO THU440-A, THU451, 10A-A, THU826-A, THU407 flush valve assemblies. Designed as reliable toilet replacement parts to maintain proper tank sealing performance，Fits old style Hi-Flow square style flush valves (415042, 415043, 415047 or 415056) 【Reliable Flush Valve Seal】 Ideal for TOTO flush valve replacement, this gasket restores tight sealing, improves flushing efficiency, and prevents water from continuously running into the bowl 【Leak Prevention Design】 Works as a durable toilet seal ring between the flush valve and tank base, helping fix slow leaks caused by old, deformed, or bubbled gaskets 【Durable Silicone Material】 Constructed from high-quality silicone with strong elasticity, wear resistance, and aging resistance, providing a long-lasting solution for TOTO toilet replacement parts needs 【Easy DIY Installation】 No special tools required. This DIY-friendly kit allows homeowners or plumbers to quickly replace worn gaskets, saving time and repair costs while improving toilet performance Suitable for Toto flush valve silicone seals THU440-A THU451,10A-A, toilet accessories and repair silicone seals, flush valve silicone seals, silicone flush valve seals outer diameter 80 mm inner diameter 54 mm thickness 3 mm outer diameter 3.125 inner diameter 2.125 inches.