Item Type: TBR30UU Linear Ball Bearing Slide Block Material: Aluminum Alloy Inner Diameter: Approx. 30mm / 1.1in Length:Approx. 91mm / 3.5in Width: Approx.75mm / 2.9in Height: Approx. 48mm / 1.8in Package List 1 x Bearing 1The surface oxidation treatment is beautiful, corrosion resistant, dustproof and prolongs service life. 2Universal ball bearings are ideal for replacing damaged ball bearings in your device to improve efficiency and save energy. 3Made of aluminum alloy material, strong bearing capacity, smooth movement, low friction, high rigidity, long service life. 4High quality bearings, exquisite workmanship, high accuracy, economical and easy to maintain and replacement. 5It is widely used in electronic devices, packaging machines, equipment, robots, tools, machines, machine tools, etc.