1" Bearing UCP205-16 + Pillow Block Cast Housing Mounted BearingsUCP205 16 Black Oxide Plated Insert Bearing + Pillow Block Housing Set Screw Type High Center Height 1" inch Inner Diameter UCP205 16 Pillow Block Bearing, UCP205 16 is Set Screw Type High Center Height, Inner Diameter is 1" inch. Black oxide has certain properties and characteristics that makes it ideal for certain applications. It is used to add corrosion resistance and for appearance. Item: UCP205 16 Black Oxide Plated Insert Bearing + Pillow Block