The HC660 HydroClean® toilet fill valve solves the two biggest reasons for water loss in toilets, miscalibration and leaks. It easily calibrates to adjust the exact amount of water needed in the tank, refills quickly and jets clean the tank. A unique feature is the leak detection and signals when a leak is found. It is designed to fit most standard toilets and the height can be adjusted from 11 to 13.8 in. The HC660 installs easily without tools.