A FOB is also known as “Foam on Beer”. It is designed to continuously keep your lines filled and flowing with beer. The FOB automatically shuts off the flow of beer when it detects an empty keg. This eliminates the foam you get from an empty keg and also the need to refill lines or purge air. When you tap a new keg with a FOB installed on your beer line, your tap will automatically pour beer with no evidence of foaming when the keg goes empty. Without a FOB installed, once your keg goes empty your tap will begin spraying and spitting foam. This results in wasted foam beer, wasted money and extra costs for labour and clean up.