Series N9, N9C Dual Check Vacuum Breakers prevent the reverse flow of polluted water from entering into the potable water supply. It consists of a brass body construction with an atmospheric vent, and NPT female inlet and outlet connections. Series N9 and N9C are designed for non-health hazard, continuous pressure applications. Series N9C comes with chrome plated finish. Maximum Working Pressure: 125psi (8.6 bar)