This is a 304 stainless steel blow off tube for Ss Brewtech 14 gallon Chronical fermenters. Fits perfectly on the 3" TC dome lids and comes with a built-in relief valve. The two-piece cane has an outer diameter of 15 mm (approx. 9/16") and 3/8" NPT where they connect. 3" TC gasket and clamp not included.