Specification Brand : HARFINGTON BulletPoint1 : Size - 8mm x 200mm (D*L). High precision with a tolerance of 0.005mm. Hardness up to 60-64 HRC. High straightness, ≤0.5/1000μm. BulletPoint2 : Material - Made of quality bearing steel, chrome-plated surface for durability and corrosion resistance. Mirror-polished for a smooth surface. BulletPoint3 : Feature - Provides low friction and high precision motion, ensuring smooth and stable linear movement while reducing wear and ensuring accurate positioning. BulletPoint4 : Application - Use with linear support blocks and enclosed sliders. Suitable for 3D printers, CNC machines, robots, automated machinery, molding machines, engraving machines, etc. BulletPoint5 : Note - Easy installation with chamfered ends to prevent fingers from getting hurt during installation. ItemName : HARFINGTON 4pcs Linear Motion Rod Shaft Guide 8mm x 200mm Bearing Steel Chrome Plated Smooth Hardened Rod High Precision Linear Motion Shaft Linear Rail for 3D Printer CNC DIY Tools ItemPackageDimensions_Height : 0.59 inches ItemPackageDimensions_Length : 8.27 inches ItemPackageDimensions_Width : 1.97 inches ItemTypeKeyword : linear-motion-guides Manufacturer : HARFINGTON Material : Alloy Steel PartNumber : hta230818hh000452 ProductDescription : Made of quality bearing steel, chrome-plated surface for durability and corrosion resistance. Mirror-polished for a smooth surface. Provides low friction and high precision motion, ensuring smooth and stable linear movement while reducing wear and ensuring accurate positioning. Use with linear support blocks and enclosed sliders. Suitable for 3D printers, CNC machines, robots, automated machinery, molding machines, engraving machines, etc.