Material: Made of high quality steel. Heavy duty steel construction. Good performance. Higher corrosion resistance, not easy to rust, more durable. Good performance. Can be used with confidence. Size: Wire Diameter: 7mm/0.28", Length: 106mm/4.17". Sturdy, solid, can hold up to 200 kg (440 lbs) for 1 piece of spring and 400 kg (880 lb) for 1 pair of springs. Function: The spring helps relieve the stress of shocks, provides a more comfortable and softer feel, and will increase the life of your hammock, in addition to your mounting surface. Simple assembly: With hooks at both ends, the swing spring porch swing easily connects to your hammock chair without using any tools or complicated operation. Versatile: Suitable for almost any porch garden deck and garden swing, hammock, hanging chair, carrying bag knock, cocoon, rattan chair wicker basket, etc. Feature: brand new and high quality Made of heavy-duty steel, zinc-plated for better weather resistance. Helps reduce impact stress and provides comfort; increases the life of your hammock and mounting surface. Suitable for almost any punching bag, hanging chair, hammock chair, cocoon, egg chair. Specifications: Loading capacity: 200kg / 440lb (for 1 piece of spring), 400kg / 880lb (for 1 pair of springs) Material: Steel Size: Length 106mm Colors: Silver Quantity: 4pcs Package Included: 4 x Spring Hook Notes: 1. Please allow 1-3cm error due to manual measurement. Please make sure you do not mind before you bid. 2. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Please take the real one as the standard. Thank you! 3. Remember to check the condition of the hammock extension spring before use.