A beer shank is installed through a wall or a refrigerator door and connects to the faucet and the beer tubing. This beer shank has a 3/16 inch inside diameter bore. The chrome plated beer shank comes in two sizes. Please chose a size from the drop down menu. The two sizes are 4 1/8" in lenght and 5 1/8" length. The most common size used to pass through a refrigerator door is 4 1/8".