Stainless steel tank nipple. Requires 9/16″ diameter hole for welding tank nipple into place. Takes both gas and liquid dip tubes, has 19/32″ -18 thread and takes the Cornelius gas and liquid keg post used with a universal poppet valve. Add a keg post to any vessel to allow the use of keg disconnects. Other parts sold separately eg. keg post, poppet valve and gas/liquid dip tube.