This Perlick 308-40C Wrap-Around Faucet Tap Lock is perfect for bar owners and managers who want to stop unauthorized draft beer pouring after the bar closes. It works well with Perlick 630 beer faucets. You just need to give it a snug fit, and it'll do its job. There's no complex setup. It's an easy way to keep your draft beer secure. Remember, it won't fit MicroMatic, Stout (Guinness-style), or European-style beer faucets.