The Mustad Barrel Swivel with interlocking snap is very strong, dependable and easy way to change your lure, weight or leader. When choosing a swivel always go small. Pick a swivel, which will match the breaking strength of your line. This will give the best performance and presentation. When tying your fishing line to the swivel eye make sure to center the knot, as this will ensure the best rotation. Made from brass, for either saltwater or freshwater use.