TOTO TET1GNC-32 Exposed Eco 1.6 Gpf Efv W Vb9Cp-32 Accessory Kit, Chrome Revolutionary EcoPower hydropower self-generating system Automatic sensor activated, piston toilet flush valve Positive Seal: No warpage or mis-seals No valve resetting after water pressure loss Consistent Performance: Works with low (15psi) or high (125psi) waterpressures