Material: The sturdy spring is made of high quality galvanized iron, corrosion-resistant, smooth and durable. Load Capacity: The load capacity of the hammock spring is up to 500kg, which ensures your safety during use. Wide Application: The spring hook is used for hanging chairs, hammocks, porch swings, rocking chairs, trampolines and heavy bags. Feature: The spring design makes the hook with higher tensile strength, better elasticity and stronger stretchability. Size & Package: The size of the trampoline spring is L108 x W39mm, each package included 2pcs trampoline springs.