Industrial-grade standard block, with high precision linear inside. Surface silver plating treatment, beautiful anti-rust, hardness can as high as HRC62, more durable. The adjusting handle can adjust the tightness of the slider. Standardized processing, perfect for guide rail positioning. Perfect for your DIY CNC routers, mills, lathes. Aluminum alloy support rail with -drilled holes for ease of mounting. Type: Linear slide guide Glide path: linear guide Rated dynamic load: 860 Rate static load: 1370 Precision grade: H Fixed bolt size: 8 (mm) Fixed mode of sliding block: Locking type Allowed static : 1 (kn.m) Weight:1050g colour:Silver Material:metal size: Linear Slide Rails- 500mm / 19.7inch (Length) x 12mm / 0.47inch (Diameter); Linear Side Blocks -40mm x 40mm x 28mm/1.57 x1.57 x1.10inch( Length x Width x Height) Package Contents: 1 x linear guide 2 x Linear slider Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.