The American Fishing Wire Double-Barreled Leader Sleeves are perfect for crimping over wire and monofilament to create your own leaders to use when fishing for toothy critters. The copper sleeves have a smooth, burr-free finish that won't damage your line. Ideal for making end loops in the leader material, the American Fishing Wire Double-Barreled Leader Sleeves have thin walls that are perfect for monofilament, fluorocarbon, or wire leaders. Perfect for creating your own leaders; Ideal when chasing toothy predators; Smooth copper sleeves won't damage your line; Thin walls compatible with monofilament, fluorocarbon, or wire;