High-quality materials: The linear guide is made of high-quality carbon steel, and the bearing seat is made of aluminum alloy, which is sturdy and durable. High hardness: hardness can reach HRC62, more durable. Silver-plated surface, good rust protection. Standard industrial grade SBR block. Built-in high-precision linear bearings. It can move smoothly, with minimal wear and low noise Easy to install: Aluminum alloy support rails are equipped with pre-drilled holes for easy assembly. Application: Standardized processing, very suitable for guide rail positioning. It is widely used in automatic machinery such as machine tools and bending machines. Specification: The length of the guide shaft: 300 mm. Rail diameter: 12 mm. Slider size: 39 x 40mm. Weight: 1380 grams Colour:silver Material:Carbon steel Package Contents: 2 * linear guide axis 4 * bearing sliders Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.