The size ranges from 200mm to 1500mm in length. How many pieces are included? There are 2 rails and 4 blocks included in the package less effort for maintenance. DIY CNC machine,automation machine,robots,equipment parts. HGR15 Linear bearing rails made of quality bearing steel. Linear Guide Rail Set Linear Rail Guide Machines Kit Milling Machine Use 4Pcs Blocks GW15CC DIY CNC Machine Linear Rail Each order includes two matching linear guides (left and right rails) for immediate installation. Perfect for building X/Y-axis systems or upgrading existing CNC equipment. Designed for straightforward mounting on gantries, frames, and worktables. The standardized dimensions ensure compatibility with most CNC router setups for hassle-free upgrades HGR15 This linear guide rail set includes : 2 PCS HGR15 -7., 87 inch(200mm) Linear Rail+4 PCS HGH15CA Slide Block , 2., 4 HGH15CA Bearing pillow blocks with smooth sliding., Low noise., 3., HGR15 Linear bearing rails made of quality bearing steel. Linear Rail guide 2PCS HGR15 Linear Guide Rail HGR15-7., 87 inch (200mm) Linear Slide Rail with 4PCS HGH15CA Linear Bearing Blocks This linear guide rail set includes : 2 PCS HGR15 -200mm Linear Rail+4 PCS HGH15CA Slide Block 4 HGH15CA Bearing pillow blocks with smooth sliding., Low noise. Linear Guide Set | Linear Rails | Hgr20 Block | Hgh20ca | Hgh15ca - Eu less effort for maintenance., 5., Wide Application: The linear guide rail is widely used in automation machinery such as DIY CNC routers, lathes, machine tools, bending machines, laser welding machines, etc.