PREMIUM MATERIAL: These swinging springs are made of high-quality steal, heat treated, powder coating. You can use them both indoor and outdoor, on your patio, porch, tree and ceiling mount. VARIOUS APPLICTIONS: These heavy-duty hanging springs are tightly coiled for shock absorption. You can use them for swing benches, hanging chairs, hammocks, hammock chairs, and punching bags, you can also use it for industrial application where need reduce vibrations and avoid shocks. PLUG AND PLAY: Simply Connect to your hammock and accessories and go. You can install it or replace the existing ones within minutes. WEIGHT CAPACITY: We offer two colors black and silver, two capacity 600lbs and 750lbs. You can chose either buy one or two in one set according to your applications. SAFETY: A plastic cap are covered the end of the wire to prevent scratching fingers or hanging ropes, it also prevents springs from falling off from the hokes. The premium heavy-duty wire ensures never broken under heavy load.