This is a rather simple, but extremely effective way to fill growlers from your draft system! Going to a party, but don't want to bring a keg of homebrew? Filling straight from the faucet creates a lot of foam, and you lose carbonation. Simply plug this filler into your faucet, attach some 3/8" tubing, and fill! This model is designed to fit the Perlick faucets, as their inner diameter is different than standard faucets. If you own a standard faucet, please checkout our D1222. Faucet insert OD is 13/32" Make sure to check your Perlick faucet ID as it may not work with older models. Please Note: This product will not work with our Perlick Flow Control faucets, as these have a slightly smaller spout.