The LDR Industries 12 in. (1/2 in. M.I.P. & 1/2 in. Sweat) Chrome-Plated Anti-Siphon Frost-Proof Sillcock features a built-in backflow preventer, convenient notched flange and neoprene seal disc. LDR offers a complete line of high quality valves to fit a wide variety of applications and connection types. All valves meet ANSI standards and ASTM standards and are 100% pressure tested. Our valve program is color coded for ease of shopping by the consumer. LDR brass hose end valves are generally used for irrigation purposes. The LDR anti-siphon sillcock is an exterior wall valve used for garden hoses. The frost-free sillcock extends the inside wall away from cold weather and prevents frozen pipes and freeze breaks.