50mm Bearing UCP210 Black Oxide Plated Insert + Pillow Block Cast Housing Mounted BearingUCP210 Black Oxide Plated Insert Pillow Block Bearing Set Screw Type High Center Height 50mm Inner Diameter UCP210 Black Oxide Plated Insert Pillow Block Bearing, UCP210 is Set Screw Type High Center Height, Inner Diameter is 50mm. Black oxide has certain properties and characteristics that makes it ideal for certain applications. It is used to add corrosion resistance and for appearance. UCP210 Black Oxide Plated Insert Bearing + Pillow Block Housing