The Danco toilet repair kit solves the two biggest sources of water loss in toilets-miscalibration and leaks. The mini-valve allows pinpoint calibration which saves water. The automatic leak detection feature continuously monitors toilet sustainability and signals when a leak occurs. It also cleans the tank and flapper with powerful jets that prolong the life of all internal components and eliminate the need for harsh, toxic chemicals that are a source of contamination in and around your home.