This 3/8' stem with built-in 1/4' MFL swivel nut is used to attach the swivel nut fitting to any male flare thread fitting. From there you can attach your 5/16' or 3/8' inside diameter tubing. Note: these are the same Fittings used to attach your hose to a gas ball style quick Disconnect or gas pin style quick Disconnect. Features: made of chrome plated Brass. 3/8 inch barb to 1/4 inch swivel nut, country of origin - United States, manufacturer name - Fittings, Inc.