Attached to sill cocks, valves, and hydrants with Male hose thread outlet. For indoor or outdoor use. Designed to prevent dangerous back siphonage and back flow. Furnished with break-a-way lock screw if vandal-resistant installation is desired. For nonfreezing areas only. Designed to protect hose connections from contamination where temperatures do not get below freezing. Outlet side of vacuum breaker has a manual drain release of check valve to allow complete draining of valve, but must be operated manually after hose is disconnected to prevent valve from freezing. I.A.P.M.O. and A.S.S.E. approved. 1 each per display pack for peg hook hanging. Import.