400LS Universal Fill Valve, Leak Sentry® - Fluidmaster
Best of all, when there's no leak in the tank, it works just like a 400A toilet fill valve, so you know you'll get consistent performance flush after flush. Automatic "Locking" action alerts users to leaks before money and water are wasted. Toilet remains fully operational, easily resets with touch of tank lever. Anti-siphon, code approved.