Constant Pressure Two-stage regulator Oxygen Outlet 9/16” Inlet CGA-540,CGA-540 Constant Pressure Two-stage regulator Oxygen Outlet 9/16” Inlet, Outlet connector: 9/16" Male and Hose Barb - Inlet Connector: CGA-540 - For use with Oxygen, These products are intended for professional or trained users,Inlet Connection: CGA-540 - Outlet Connection: 9/16”-18 RH, Low prices storewide Same day shipping Get the best quality products from our store. Inlet CGA-540 Constant Pressure Two-stage regulator Oxygen Outlet 9/16”.