The barrel swivel is used to connect the line leading from a rod to a lure to untwist the line to avoid tangling during retrieval.SpecificationColor: BlackStrength: 17kg / 37 lbsMaterial: Stainless SteelSurface Treatment: PolishingOverall Length: 18mm / 0.71 inchRing Inner Diameter: 3mm / 0.12 inchPackage Content: 100 x Fishing Barrel SwivelsAdvantage1. This swivel connector is made of polished stainless steel. Smooth surface will not cut fishing line.2. Barrel swivel can ensure 360-degree rotation flexibility under strong tension, thus reducing twist to a minimum.InstructionJust tie the fishing line connected to the fishing rod to the ring of the swivel.NOTE: Please confirm the size and strength of the snap swivel you need before ordering.