This is a set of Pin Lock Becker Home Brew MFL Couplers. This set includes both a gas in and beer out coupler that works with a pin lock Cornelius Coke kegs. The Gas In and Beer Out Couplers feature a 1/4" thread for a flare fitting. The 1/4" MFL fittings allow you to easily remove your gas/beer lines from the coupler connector already.