Ideal for hard to fit picnic coolers, this stainless bulkhead requires a 7/8" (22mm) hole in your cooler or pot, and features silicone O rings with containment nut on both ends. Adds a 1/2" male NPT outlet to a thick cooler or pot. The maximum thickness this will accomodate in a plastic cooler is 1½" thick. The overall length of the threaded bulkhead is 2½" long. The side facing the interior of the pot is smooth and not threaded.