FAG Tapered Roller Bearing, Model No.-30203, It is amachine elementthat constrains relative motion to only the desired motion, and reduces friction betweenmoving parts. The design of the bearing may provide for freelinearmovement of the moving part or for freerotation around a fixed axis. It is being a machine element that allows one part to bear (to support) another, Specifications: Outer Diameter-40mm, Inner Diameter-17mm, Width-13.25mm, Warranty- As Per Manufacturer's Warranty Policy, (Pack Of 1)