TOTO Auto Flush Kit For S7 & S7A Washlet System Single Flush Toilets - THU857TOTO Auto Flush Kit For S7 & S7A Washlet System Single Flush Toilets THU857 Auto Flush Kit For The Washlet S7A And S7 Bidet Seats Only Compatible With Single Flash 1. 28 And 1. 6 Gpf Toto Washlet+ T40 Toilets Designed specifically for TOTO WASHLET+ T40 toilets utilizing single flush configurations (1. 28 or 1. 6 GPF). Works with Washlet S7A and S7 bidet seatsbut not compatible with dual flush setups or other Washlet models like S550e, S500e, or round