Features: 1. Made of high quality carbon steel material, the magnet can be sucked firmly.2. With Nickel plating in the surface, which can effectively prevent rust.3. Used CNC machine molding, to ensure the product accuracy. Specifications: -Ball diameter: 12mm-Screw thread: M5-Total lenght: 35mm -Thread length: 20mm Package Included: 3 x 12mm M5 Ball Screw