1、Surface oxidation treatment, beautiful and corrosion resistant. Smooth moving, low friction, high rigidity and long life. 2、Aluminum alloy material, stronger bearing capacity. High quality bearings, exquisite workmanship, high precision. 3、Surface oxidation treatment, beautiful and corrosion resistant. Prevent dust from entering and prolong service life. 4、Applied to electronic equipment, packaging machinery, medical machinery, printing machinery, textile machinery, machine tools etc. 5、The universal ball bearings is great for you to replace the damaged ball bearings in your devices to improve them efficiency and save energy. 1 x Bearing Item Type: Slide BlockMaterial: Aluminum AlloyInside Diameter: Appprox. 12 mm/ 0.5inLength: Approx. 40 mm/ 1.6inWidth: Approx. 39 mm/ 1.5inHeight: Approx. 27.6 mm/ 1.1in