Item Type: Linear Ball Bearing Model: LM25LUU Material: Bearing steel Inner Diameter: Approx. 25mm / 0.98in Outer Diameter: Approx. 40mm / 1.57in Length: Approx. 112mm / 4.41in 1,Stable Performance: This linear motion bearing can move smoothly with low friction, stable rotation process, low noise and high speed, high bearing accuracy, fast running speed and low friction torsion. 2,Exquisite Craftsmanship: After a special heat treatment process, advanced manufacturing equipment and technology to make the bearing life greatly increased, for the high requirements of the equipment not easily disassembled can save money. 3,Great Replacement: This set contains 2 linear motion bearings for you to use, you can directly replace the old or broken ones, it is good replacement parts. 4,Bearing Steel Material: This linear motion bearing of ours is made of bearing steel material with heat treatment, high rigidity and drop resistance for long term use. 5,Widely Used: Long linear motion bearings can be widely used in 3D printers, various CNC machine tools, if you have related needs then this one is suitable for you.Measurement may have error. Please make sure you don't mind before ordering.2 x Linear Ball Bearing