PREVENTS BACKFLOW OF WATER — From a handheld shower head into the water supply. Ideal for institutional, hospitality, residential use, and anywhere required by local plumbing codes. ASSE 1014-2020 PLUMBING STANDARD — Compliant, tested, and Certified. MASSACHUSETTS Uniform State Plumbing Code (248 CMR 10.00) approved. MINIMAL PRESSURE LOSS — Less than 5 psi. Solid brass housing. Standard 1/2-Inch NPS connections. CONNECTS — Between the water supply and handheld shower hose. NO TEFLON TAPE REQUIRED. RUBBER WASHERS INCLUDED — To seal both ends of the vacuum breaker. Replace existing shower hose washer with washer supplied by High Sierra. IMPORTANT: Failure to use the included washers may result in shower head pressure loss. Engineered and assembled in the USA with imported components. Available in 6 beautiful finishes.