Salco Products (SP31254CS) 5/16 x 4-Inch (5/16"x4") Carbon Steel Seal Pin Assembly features a carbon steel seal pin that is 5/16-inch thick with 4-inches of usable length, and an overall length of 5-1/16-inches. The toggle (flapper) holds the pin in place, and features an elongated 3/16-inch seal hole. Welded to the end of the pin is 13 links of 1/8-inch, zinc plated carbon steel, chain with a length of 12-inches.