This shutoff valve can be used for multiple applications. Has a 1/4 in MPT thread on one side, this is commonly used in regulators, air distributors, and other keg system components. The out side has a 1/4 in MFL fitting for attaching a variety of flare fitting such as a barb ans swivel nut for gas lines. Includes a check valve, so gas can only flow in one direction, this can protect your regulator from accidential back up of beer.