MidWest Swivel Snaps are used to secure MidWest Exercise Pen panels together. Swivel Snaps open and close smoothly. They have a strong spring loaded snap gate opening. Swivel Snaps can be used with any metal exercise pens. For best results, place thumb snaps at the top and bottom of the excercise pen between the two closely spaced wires, and space the remaining two snaps evenly along the middle wires. The snaps will keep your exercis pen securely closed. Swivel thumb snaps have many other uses as well. Some of which are making pet leash clips, harnesses, reins, bag shoulder straps, hip bags, horse blankets, keychain fobs, and lanyards plus many more! Good for securing flags too!