This fitting is designed to thread into the inside of a bulkhead fitting, and clamp down on a copper or stainless tube. This can allow you to make a hard-plumbed false bottom in a homemade mash-tun. It can also be used on a dip tube, a HERMS coil, or cooling coil in a fermenter.
To use, simply thread the fitting into your bulkhead, loosen the nut, and slide your tubing in. Tightening down the nut with tubing inside will clamp the internal locking mechanism onto your metal tube, creating a tight seal.
304-Type Stainless Steel compression fitting. 1/2" Male Pipe Thread, with a 3/8" compression fitting on the other side.