Ball Lock Disconnect with Built in Check Valve (Gas)
This ball disconnect has an internal check valve that will allow the gas to flow out, but won't allow back-flow of liquid back into your system.  Protect your CO2 regulator from back-flow of beer or soda with these German made check valved disconnects.
Simply attach a Swivel Nut with 5/16" Barb to the end of the disconnect and clamp on your CO2 Gas Hose.