Polymer SBR12UU 12mm Low Noise Linear Motion Ball Bearing Pillow BlockPolymer SBR12UU 12mm Low Noise Linear Motion Ball Bearing Pillow Block Polymer SBR12UU 12mm Linear Motion Ball Bearing Pillow Block. New solid polymer material, lightweight, good wear resistance and strength, more stable and help to reduce noise Solid Polymer SBR12UU Bearing Linear Ball Bushing Inner Contact Diameter: 12mm Improve them efficiency and save energy. Quantity: 1 Bearing No oil needed,Self lubricating, Dust proof. Improve them efficiency