Features: 100% brand new and high quality. Good wear resistance and strength, high accuracy, not easy to rust. Has good performances, low friction coefficients and long usage spans. Suitable for industrial automation equipment, such as 3D printers, engraving machine,etc. Convenient to install, great parts to built projects or replace old ones. Specifications: Material: Steel(rod), aluminum Linear Rod Diameter: 8mm Linear Rod Length: 400mm Sliding Block Inner Diameter: 16mm Sliding Block Hole Diameter: 8mm Sliding Block Length: 33mm Sliding Block Height: 21mm Rod Support Hole Diameter: 8mm Rod Support Length: 41mm Rod Support Height: 32mm Weight: 301g(approx.) Package Includes: 1 x Linear Rod 2 x Sliding Blocks 2 x Rod Supports