Gas-In - Homebrew - Ball Lock Fitting 5/16" Barb Beer Keg Tap Product Highlights: Fits the most commonly used Home Brew tank (a.k.a. Corney Keg) gas (in) port. Specifications: PortGas-In ConnectionBall Lock Type Stainless Steel Barb Fitting5/16" O.D. Note on Keg Coupler: When using Homebrew fittings it is recomended to use either an inline check valve or regulator shutoff(s) with a built in check valve. This is because Homebrew fittings do not have a built in check valve and check ball (standard in keg couplers). These features prevent the possibility of beer backflowing into the gas regulator and possibly causing damage.