Gas Regulator, Regulator Supply Type Cylinder, Gas Service Oxygen, Stages Two Stage, Inlet Connection CGA-540, Outlet Connection 9/16 In. -18 RH, Delivery Pressure Range 125 psi, Gauge Size 2 in, Supply Pressure Gauge 4, 000 psi, Max. Inlet Pressure 3, 000 psi, Body Material Solid Brass, Diaphragm Material Neoprene, Body Dia. 2.0 in, Includes External Relief Valve, Nickel-Plated Bonnet, Sure Seat (TM) Filtered Seat, Standards UL Listed. This item has been restricted from sale in the following state (s): []