Miniature Ball Bearing, Bearing Industry Number 638, Bore Diameter 8 mm, Closure Double Sealed, For Environment Oily/Greasy, Outer Ring Width 9 mm, Outside Diameter 28 mm, Ring Material Alloy Steel, Seal Type Contact, System of Measurement Metric, ABEC Rating 1, Ball Material Alloy Steel, Ball Material Grade AISI 52100, Bore Diameter Tolerance +0/- 0.008 mm, Cage Type Sealed, Dynamic Radial Load Capacity 1, 020 lbf, Includes Retaining Ring No, Lubricant Material Polyrex EM. This item has been restricted from sale in the following state (s): []