This linear guide rail kit is designed for DIY CNC routers, lathes, and mills that need precise linear motion and smooth operation. The set includes dual HGR20 rails, four slide blocks, a ballscrew, ball nut, BF12/BK12 nut set, and a plum coupling for a complete motion setup. Built with steel components and chrome-plated surfaces, it is made for durability, corrosion resistance, and reliable performance. Pre-drilled mounting holes help simplify installation, while the design supports low-noise movement. It is well suited for automation machinery and precision measuring equipment.