Salco Products (TC3N60P3A) 3-inch Nitronic 60 Plug Assembly with Stainless Steel Chain consists of a plug that has 3-inch NPT threads, and is made out of Nitronic 60 material. The width across the flats of the head is 3-1/4-inches. Length of the thread is .94-inches with the overall length of the plug being 2.69-inches. Comes with a stainless steel chain assembly that consists of a 1/4-inch, 304 stainless steel, swivel link that is crimped around the plug, and is connected to a 3/16-inch, 18-8 stainless steel, chain of 15 links with an approximate length of 19-inches.