Available in these sizes (all length x open inside diameter x jaw inside length xpin inside length): 2-3/4"x1/2"x3/8"x3/8",3-1/2" x5/8"x1/2"x1/2",
5"x1"x7/8"x7/8".use this shackle as a way to attach my dog's leash to his collar. It works wonderfully.