The Duotight Flow Stopper - Automatic Keg Filler (KL09393) is an fantastic device designed to streamline the keg filling process for homebrewers. This product,  offers a hassle-free method of filling kegs, or transferring between kegs during filtering or after fining. It is particularly useful because it attaches to the gas post of your keg and automatically cuts off the flow once the keg is full, thus preventing overfilling and spillage of beer. Some of its key features include compatibility with Duotight fittings, ensuring a secure and leak-free connection, and the ability to work with a BlowTie spunding valve. When used with the BlowTie, it allows you to apply head pressure to the keg, enabling control over the flow speed and reducing foam during the filling process.For this setup, a short length of 8 mm OD EVABarrier tubing is required to connect the BlowTie to the outlet of the Flow Stopper. This flow stopper includes:2 x duotight 5/8" thread x 8mm pushfit (for hose)1 x duotight Elbow pushfit 8mm1 x duotight straight 8mm pushfit x 7/16" thread for threaded ball lock1 x ball float1 x stainless spring1 x acrylic sight glass (with 5/8 male thread on either side)*Colours of the floating ball and joiners may vary. You need to buy a ball lock with a thred if you do not have one.