Prevents endless refilling of leaky tanks. Adjustable bowl refill prevents wasteful overfill. Unique ``locking" action reveals leaks immediately. Ideal for hotel/motel and multi-housing applications, homes and seldom-used bathrooms. Fits most toilets, including 1.6 gpf models. Toilet always remains operational. Made of corrosion-resistant materials that withstand harsh water and constant use. Meets all anti-siphon codes.