17mm Bearing UCP203 Black Oxide Insert + Pillow Block Cast Housing Mounted BearingUCP203 Black Oxide Insert + Pillow Block Cast Housing Mounted Bearing Set Screw Type High Center Height 17mm Inner Diameter UCP203 Pillow Block Bearing, UCP203 is Set Screw Type High Center Height, Inner Diameter is 17mm. Black oxide has certain properties and characteristics that makes it ideal for certain applications. It is used to add corrosion resistance and for appearance. UCP203 Black Oxide Insert + Pillow Block Cast Housing Mounted Bearing