Salco Products (TC075416PHA) 3/4-inch Stainless Steel Plug Assembly with Seal Hole and Stainless Steel Chain consists of a plug that has 3/4-inch NPT threads, and is made out of 416 stainless steel material with a .19-inch seal hole drilled through the head. The width across the flats of the head is 1.06-inches. Length of the thread is .63-inches with the overall length of the plug being 1.07-inches. Comes with a stainless steel chain assembly that consists of a 1/8-inch, 304 stainless steel, swivel link that is crimped around the plug, and is connected to a 1/8-inch, 18-8 stainless steel, chain of 15 links.