Reverse Flow Check Valve Set, Mounting Location Regulator, Compatible Gas Type Fuel, Oxygen, Inlet Connection Size 9/16 In.-18, Outlet Connection Size 9/16 In.-18, Inlet CGA Number (Fuel) CGA 023, Inlet CGA Number (Oxygen) CGA 022, Hose Fitting Size B, Body Material Brass, Inlet Connection Type UNF, Inlet Thread Direction Left Hand, Right Hand, Product Type Check Valve Set, Series H698, Standards UL Listed