1.Material: Made of high quality steel.Sturdy steel construction.Good performance. Higher corrosion resistance, not easy to rust, more durable. Good performance. Can be used with confidence.^ 2.Size: Wire diameter: 7mm, Length: 108mm. Sturdy, strong, can support up to 200 kg (440 lb) for 1 piece of spring and 400 kg (880 lb) for 1 pair of springs.^ 3.Function: The spring helps relieve the stress of shock, provides a more comfortable and softer feeling, and will increase the life of your hammock, besides your mounting surface.^ 4.Simple Assembly: With hooks at both ends, the porch swing spring easily connects to your hammock chair without the use of tools or complicated operation.^ 5.Versatile: Suitable for almost any patio porch and garden swing, hammock, hanging chair, punching bag, cocoon, rattan chair wicker basket, etc.