The 400UK will work in most toilets including some 1 Piece toilet models. To see if the fill valve will fit in your toilet measure the flush valve drain (overflow pipe) from bottom of the tank to its open ended top. If the flush valve drain is 6 inches or taller the 400UK valve should fit. Some toilet models not supported would be Flapperless, Low Bay 1 Piece Toilets and Side Entry Valves.
Replaces ballcocks universal fill valve
Easy to install
Height adjusts 9″-14″
Universal fit for 1 and 2 piece toilets
Anti-siphon operation, code approved
Won’t contaminate fresh water supply