This is an essential item to prevent twisting and kinking of your wing's hand leash! (Especially since the loop cord on the wing itself cannot be replaced due to deterioration, preventing twists is the key to making your wing last longer.) How to use: Simply insert it between the wing body and the leash cord. → ① Relieves hand stress caused by leash twisting & ② Prevents leash breakage due to accumulated twisting! The swivel weighs only 13g (No impact on wings that are sensitive to weight!) Made of rust-resistant brass, Tensile strength is 200kg (according to the manufacturer), Size is 10 x 34mm, with a 6mm inner diameter hole. A high-strength 4mm cord is included, but you can customize it to your liking. Sets of 2 or more are also available. (Set prices) 2 for 1500 yen 3 for 2100 yen * Cord colors are black or white. → Please comment in advance if you want multiple sets. (I will change the display and price.) As this is a personal sale, I cannot guarantee performance, but I have been using it for 3 years without replacement. There is no damage, deformation, or rust, and tangling at hand is greatly reduced during turns.