The Woodford 34HD-CH Vacuum Breaker is a NIDEL® Model 34HD Anti-Siphon Vacuum Breaker. It is designed to protect hose connections from contamination where freezing temperatures are expected. It requires manual draining and it provides easy, sure drainage during cold weather. This Woodford 34HD-CH Vacuum Breaker has a brass and stainless steel construction which make it more dependable and long-lasting. This single-check vacuum breaker from Woodford ha a molded rubber diaphragm check valve. It has a 3/4"female hose thread inlet and a 3/4″ male hose thread outlet nozzle. It also features a stainless stop collar and stop screw which makes it theft-resistant. This vacuum breaker comes with a chrome finish. This device is ASSE 1011 approved. The Woodford 34HD-CH Vacuum Breaker is another quality product from Woodford that can give you years of trouble-free service. Woodford is today's premier manufacturer of wall faucets, yard hydrants, vacuum breakers and bath/lavatory drains and trim kits. All of Woodford's products is proudly made in the USA.