Polyurethane rubber: The special material does not hurt the stone, the texture design increases the friction, and the stone will not slide off easily Quality screw accessories: Selection of first-class hardware accessories screws, durable, non-slip more convenient and safer Lifting Clamps: Chain length adjuster, , non-slip and wear-resistant, comfortable to use Alloy steel forging: High-grade alloy steel, forged and processed at high temperature, is safe and has a long service life