Features: brand new and high quality Made of high quality stainless steel material, have proven to be long lasting and provide precise low friction linear movement. These ball bearing with double side rubber seal to prevent ingress of dirt, water and foreign matter. Smooth moving, low friction, high rigidity and long life. Economical, easy to maintain replace. Have excellent rotating accuracy,can prevent tilt friction between the roller of roller. Can be widely used in automation equipment , electronics, instrument ,robot ,packaging machinery,CNC machinery. Specifications: Item:Prusa I3 MK2/MK2S/MK3 U-bolts+Straight Line 8UU+M3 Gasket Kit LM8UU Linear Ball Bearings Length:24mm/0.94in Used for：Prusai3 MK2/MK2S/MK3 3D Printers Material:Stainless Steel+Rubber Package Includes: 10 X LM8UU Bearings 3 X U-Bolts 6 X M3 Locking Screws/Gaskets note: Due to the problems of lighting effects and shooting angles, there will be certain tolerances in the product, please understand. Please allow 0-1cm error due to the manual measurment.