Fits for P204/F204/FL204/T204/PA204/FA204/FB204 and More Bearing Housings. UC203 bearing and seal kit Interchange Numbers:UC203, UC203-17MM, UC203D1 UC203 is an Insert Ball Bearing with two set screws on the extended end of the inner ring used for holding onto a shaft.This UC203 Insert Ball Bearing is self-aligning for standard load capacity. The UC200 Series Insert Bearing are widely used as replacement bearings for Pillow Blocks, 2-Bolt Flanges, 3-Bolt Flanges, 4-Bolt Flanges, and Take-Up Units.It can be costly to replace the whole unit however, buying just the replacement for the insert bearing can save you from over spending UC203 Insert Ball Bearings are used in a range of applications from Agricultural Machinery, Conveying Equipment, Construction Equipment, Packaging Equipment, Material Handling Machinery, Aggregate Crushers, Conveyor Systems, Shaft Supports, Food and Beverage Processing, and in the Printing Industry.