Description TOTO THU SERIES 3-inch Flush Valve Toto Drake & Eco Drake Toilets Two Piece Model – #CST743 (round), #CST744 (elongated) Tank #ST743 – G-Max Flushing System 1.6 gpf Tank #ST743E – E-Max Flushing System 1.28 gpf Also fits Toto THU Series One-piece or Two-piece toilets 3 compact flush 3-inch flush valves Works with various Toto models THU451.10A-ATHU443.15K-A THU440-A THU 82A THU 451 THU831-A THU460.15E-A THU002N Optional: Extra seals to extend the life of your valve, simply replace the 80X54mm Seal! 3.2-inch flush valve for one-piece (tank and bowl are connected) or two piece toilets(tank and bowl separate) Leaving more water in the tank allows to control the power of your flush Easy install Durable Nuflush Design with Quality checked materials Ron (owner of Nuflush) Explains the Toto Half Canister Flush Valve Easy Measuring Tips – Video