Radial Ball Bearing, Bearing Industry Number 61904, Bore Diameter 20 mm, Closure Double Shielded, Outer Ring Width 9 mm, Outside Diameter 37 mm, Ring Material Alloy Steel, System of Measurement Metric, Cage Material Steel, ABEC Rating 1, Application Radial and Thrust Load Application, Bore Diameter Tolerance +0/-10 micron, Dynamic Radial Load Capacity Not Available, Flange Diameter 40 mm, Flange Thickness 2 mm, Includes Retaining Ring No, Lubricant Material Grease WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov -