Pack of 7 High Quality RJ4JP 01 08 Sold polymer Linear bearing a direct replacement for the metal LM8UU bearing commonly used in many 3D Printers. Perfect replacment for the X and Y axis on 3D printers. Ideal for RepRap Prusa Mendel etc. Product Specification: 8mm Inner diameter. 15mm Outer diameter. 24mm Length. Replaces stock LM8UU Bearing commonly used in many 3D PrintersFits Perfectly in 3D Printer Pillow Block. Please be aware of people who leave one star reviews these only work if your rods are not bent. IF rods are bent they lock up and don’t work correctly. These do not need any lube or grease they are self lubricating. The Drylin has the lubrication built in.High Quality Authentic Igus RJ4JP 01 08 Sold polymer Linear bearingComes in Pack of 7 to replace X and Y axisLubrication is built into the polymer no need to use any oil or grease. These slowly release lubrication as they slide and using additional lubrication will decrease the life and could cause performance issues. Manufacturer: IGUS; Model: RJ4JP 01 08; MPN: RJ4JP 01 08; Part Number: RJ4JP 01 08; UPC: 633542003583; Color: ; Brand: IGUS; Department: ; Size: ; Warranty: ; Label: IGUS;