Half Inch 360 Degree Spring Loaded Swivel Trigger Snap Hook with Nickel Finish Approximate Dimensions  Overall Length: 1  inches, inside width of ID hook:  inch, inside width of round eye:  inch Full 360 degree swivel eye to prevent tangling Easy to use spring loaded trigger lever to allow quick & easy attaching/detaching Great for lanyards, key chains, pet leashes, hand bags, purses, and more Choose from 5, 10, & 20 pack sizes to suit your needs