Micromatic - U Type Keg Coupler - Tapping Head - 5/8" Thread
"U" system takes its name from the English manufacturer UEC. It is used by breweries Guinness and all other Diageo products
How to Use: When the F1 silver handle is in upright position, the piston will have withdrawn into the coupler. The valve face on the keg neck will have two teeth which match up to the receivers on the coupler.
Match it up, and the teeth sit into the groove of the coupler. Turn clockwise until it is fully held. Push the button on the handle, and then down on the lever handle to properly couple/engage the keg.