FAG Radial Insert Ball Bearing, It is a machine element that constrains relative motion to only the desired motion, and reduces friction between moving parts. The design of the bearing may provide for free linear movement of the moving part or for free rotation around a fixed axis. It is being a machine element that allows one part to bear (to support) another. Model No.-UC204-12, Specifications: Outer Diameter-47mm, Inner Diameter-19.05mm, Width-31mm, Warranty- As Per Manufacturer's Warranty Policy, Imported Bearing, (Pack Of 1)