Salco Products (TC054PA) 1/2-inch Stainless Steel Plug with Stainless Steel Swivel Link consists of a plug has 1/2-inch NPT threads, and is made out of 316 stainless steel material. It features a .188-inch seal hole drilled through the head. The width across the flats of the head is 1-inch. Length of the thread is .63-inches with the overall length of the plug being 1.34-inches. Comes with a 1/8-inch, 18-8 stainless steel, swivel link that is crimped around the plug.