PU12X28X8-2RS PU Covered Bearing 12x28x8mm - Sealed - MiniaturePU12X28X8 2RS Polyurethane Rubber PU12X28X8 2RS Polyurethane Rubber Bearing with tire 12x28x8mm Sealed Miniature PU12X28X8 2RS Polyurethane Rubber sealed Ball Bearing 12mm x 28mm x 8mm 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