... 1. Hevay-duty springs 2. CE certificate big trampoline,home trampoline,children trampoline Size:Φ2.44M ... PackageMOQ:1 setsQuality:CE certification , TUV certification.Material:Spring Net: PE,Polyethylene,High Thermodynamic & Quality Stability ... ,polished,powder coated,high-temperature baking finished Spring: Best spring steel, can operate more than 500,000 ... stand the test of time..... big trampoline