You can use pass through shanks for beer entry through the back side of a cooler. Drill a 1" hole through the cooler, insert the shank, and use the two attached nuts to tighten up on the cooler. You will need nuts and nipples of the size line you are working with as well as hose clamps. We do not use pass through shanks in our boxes because we drill a hole that is same size as the line so we can pull it back in when we are traveling. However there might be instances where they would be appropriate. Pass through shanks can also be used to put through the side of a refrigerator to pass a gas line through.,,Installation note: On a fridge there is generally no coolant lines running through the door but please check to see there are no lines connecting the door and the rest of the refrigerator. To test for coolant lines on a freezer start with a warm freezer then plug the unit in with the lid open. You should be able to see the lines form condensation on the inside of the freezer where there are lines running. Please still use caution when drilling.