Feature: 1.Every product has a unique Manufacturing Part Number label on the inner package that proves it has been qualified,which include Part Number,Model Number and inspection date information;2.If you have any questions about the item,please provide us the Manufacturing Part Number for checking,your profits will be guaranteed.3.Made of bearing steel, it's durable.4.Model is HG20, 50cm length, 2cm width, and 1.75cm height.5.Applied to machine tools, linear motion, large machinery.Note: 1.Rail guide only, block is NOT included.2.Mounting screw is NOT included.3.Please allow 1-3mm error, due to manual measurement.Specification:Color: SilverBrand name: BQLZRModel: HG20Material: Bearing SteelOverall Size: approx 50 x 2 x 1.75cm/19.69 x 0.79 x 0.69 inch(L x W x H)Weight: 1110gPackage include:1 x Linear Slide Rail Guide