Features: Made of superior material, has nice welding stability. Strong magnetismclamp attaches easily to any smooth metal surface, flat or curved. Easy to use, you can set up a ground clamp for welding jobs anywhere in seconds. Simply tack this onto a convenient spot, hook up your safety wire and you're ready to weld. The clamp can also be attached to metal poles, struts, railings or the welding table. Specifications: Material: Insulation Material + Ndfeb-Magnet + Iron Item Size: approx. 70 * 65 * 35mm / 2.75 * 2.56 * 1.38in (L * W * H) Diameter of Strong MagnetismDisc: approx. 35mm / 1.38in Magnetism: N35 (The attraction is 30kg approximately.) Package Size: 80 * 70 * 35mm / 3.15 * 2.75 * 1.38in Package Weight: 141g / 4.97ounces Package List: 1 * Welding Ground Clamp Holder