Features: Tapered roller bearings consist of outer ring, inner ring,rollers and a cage. This bearing contains tapered rollers for its rolling element which are guided by the inner ring backface rib on the roller large end face. The raceway surfaces of inner ring and outer ring and the rolling contact surface of rollers are designed so that the respective apexes converge at a point on the bearing center line. Kits with specially designed seals to keep water and dirt out and grease in. Our products are tested by the model, installation and all aspects of functions are complied with the standard. Specifications: Material:Metal Size : As Picture Shown for 50cc -250cc Item: 91683/22.5 & 91683/24 Bearings Type: Taper Roller Pressure Bearing Inner Diameter: 22.5 mm Outer Diameter: 41 mm Model: 91683/24 Inner Diameter: 24 mm Outer Diameter: 41 mm Grade: ABEC-1 Normal Quality Package Includes: 1 Set Bearings note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thanks for your understandings.