【Stable Material】The seesaw spring is made of steel and galvanized to withstand various types of mechanical damage. Galvanization protects the steel from corrosion for several years without maintenance. 【Specifications】Oscillating spring 7mm 4-speed total length: 108mm coiled wire length: 40mm wire diameter: 7mm spring outer diameter: 39mm spring inner diameter: 27mm material: galvanized steel weight: 195g 【Spring Hook Design】Use a special swing spring for the seesaw. A spring coil wrapped around the center reduces vibrations caused by floating objects. Never worry about waking up even when resting in the hammock. 【Main Functions】Swing springs are particularly suitable for attaching swings, hammocks or garden benches, porch swings, love seats, hammocks, swings, etc. in the house and garden, balcony or terrace. It is the perfect accessory to mount between the hook and the chain. 【Service】If you have any questions, please contact us.