PU12X45X14-2RS PU Covered Bearing 12x45x14mm - Sealed - MiniaturePU12X45X14 2RS Polyurethane Rubber sealed Ball Bearing 12mm x 45mm x 14mm Polyurethane ( PU) is a new type of polymer composite materials between rubber and plastic, offering higher load bearing capacity compared to plastic, polyurethane offer superior impact resistance, while good mechanical properties. Polyurethane have better abrasion and tear resistance than rubber. PU12X45X14 2RS Ball Bearing Deep Groove Ball Bearing Material: GCr15 bearing steel