Mssoomm 20mm EGW20 CNC Square Linear Guide Rail Kit - 2Pcs 21.26 inch/540mm Rails + 4Pcs EGW20-CA Carriage Slider Blocks (Low Assembly Flange Sliders) for 3D Printers, CNC Machines, Laser Cutters, and DIY Projects - Perfect for Precision Motion Control in Automation and Robotics