One dozen Bridger #2 and MB 550 Spring Pin Keepers. They are made out of 11 ga. steel, and are made for the Bridger #2 and MB 550 coilsprings with a 3/16" diameter spring pin. *NOTE* These fit Bridger #2s with a 2 9/16" wide pin. Mb 550s are only manufactured with one sized pin. Not only do these prevent Coyotes from tearing up your equipment (check out the picture), it also helps to stabilize the trap better in the bed. WELDING OR BOLTING TO CROSS FRAME REQUIRED.