This is the size that we have found to be perfect for refrigerator door conversion. It's the shank that is included in our Add-A-Tap Kit.

The chrome plated brass shank gives us a stable mounting place for the beer faucet. It requires a 1" hole (comfortable) or 15/16" hole (tight) drilled into whatever you are passing the beer through.

It includes all of the shank hardware, but you will also need a few additional items to get the beer flowing: A hex nut, a tailpiece, a neoprene washer and a clamp to secure the beer line to the tail piece. You will also need a faucet and tap handle for the other end.