UC214-44 Black Oxide Plated Axle Bearing Insert Mounted Bearing 2-3/4" BoreUC214 44 Black Oxide Plated Axle Insert Mounted Bearing 2 3 4" Inch Inner Diameter UC214 44 Black Oxide plated Bearing Insert, Bearing is standard duty, bearing is Wide inner ring with spherical outer ring, Bearing is re lubrication groove with oil hole on set screw side, bearing is nylon patched class 3A set screw, Standard seal is R Seal. Black oxide has certain properties and characteristics that makes it ideal for certain applications. It is used