Stainless Steel Cotter Pins are used to secure two items together with the use of a common hole. Place the cotter pin in the hole. The bulbous head stops the pin from moving all the way through. Included parts come in 5/32" and 3/16" eye diameter variants and run 1" to 3" in length. Full assortments of #43704 contain thirteen (13) refills comprised of Hillman item numbers #972 and #43705 - #43716.