Feature Function: The ‎VACVBKX1B vacuum breaker is used to prevent dirty water from backflowing into the clean water supply. Wide Adaptability: Designed specifically for standard frost-free anti-siphon valves, fits most standard models of Anti-Siphon, Frost-Free Sillcock Valves.Provides the peace of mind that comes with knowing your home's water supply is protected. Build To Last: Made with high-quality materials, this kit is built to last and withstand the test of time. Easy Installation: .