Performax, 2.0, High Performance Toilet Fill Valve, Works With All Toilets Including Kohler, Toto & American Standard Het Toilets, 1.28 GPF, Dual Flush, 1.6 Gallon Toilets With 2" & 3" Flush Valves & Older High Gallon Toilets With 2" Flush Valves Prior To 1994, 2 Times Greater Refill Rate Than Standard Fill Valves, Water Saving Bowl Water Level Adjustment Lets You Regulate Fill Level In The Bowl, Saving Water & Money, Anti-Siphon, Code Approved, Quick & Easy Installation.