Double Interlock Swivels Size 3/0 These swivels can be used to attach windsocks or kite tails to poles and lines. The double interlock makes it easy to clip onto the windsock where a tying is not possible. NB. They may need a little oil occasionally to prevent them from seizing. Material: Brass Barrel Swivel With Interlock Snap Length: 88mm Test: 32kg