Quick disconnects pop onto the top of the posts, one side for liquid the other for gas. The liquid side dispenses the brew and the gas side introduces the compressed gas. Most home brewers use CO2 to push and carbonate the brew or stout enthusiasts use either beer mix (Nitrogen and CO2 mix) or straight Nitrogen to push and slightly carbonate the heavier beers. The disconnects work by pulling up on the plastic lip with 2 fingers and then once placed on the post dropping down securing it into the post. We also sell the pigtails which is everything you need from each of the posts to the Tap and regulator including clamps and hoses.