This SBR linear guide rail set includes two 1000mm long SBR12 guide rails and four SBR12UU sliding blocks. Made from carbon steel and aluminum with a chrome-plated finish, it offers durability and rust resistance. The integrated ball bearings in the aluminum sliding blocks ensure smooth, non-tilted movement for effortless control. Precision measurements and straightness guarantee high accuracy, repeatability, and stability. The robust aluminum base and sliding blocks feature precise mounting holes for reliable installation. This versatile set is ideal for various automation equipment and DIY projects like CNC machines, 3D printers, laser engravers, milling machines, and lathe carriages. Shaft Diameter: 12 mm. Material: High Carbon Steel & Aluminum. Model Number: SBR12-C 1000L.