2 Pairs of M-Parts 387A Tapered Roller Bearing Cones, Inner Diameter: 2.25" for Trailer Axle Wheel Hubs (4 Included) M-Parts sells high-quality, fatigue-resistant wheel bearings for use on trailer axle wheel hub assemblies. 387A uses high-quality materials in order to ensure quality and customer satisfaction. Product Information: For use on 9K and 10K compatible trailer axle for wheel hub assemblies. This is a replacement bearing, product number: 387A Addtional Details: ✔ Helps maintain proper oil clearance ✔ High-quality material ✔ Resistance to fatigue failure ✔ Stability and reliability with high quality bearing steel alloy