Salco Products (TC025SSPA1) 1/4-inch Stainless Steel Plug Assembly with Stainless Steel Chain and Split Ring consists of a plug that has 1/4-inch NPT threads and is made out of 416 stainless steel material. The width across the flats of the head is 5/8 of an-inch. Length of the thread is .38-inches with the overall length of the plug being .74-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 12 links with a 1-3/8-inch, 316 stainless steel, split ring attached.