This tool allows the builder to correct flaws in the outer wheel hub, making it parallel to the inner hub and improve tracking of the car. The Pro Hub Shaver is an attachment that can easily be added to the Pro Hub Tool. 1. The outer hub under the axle head on most wheels is an area, which there has been no good way to correct or polish, the Pro Outer Hub Shaver will allow the builder to remove any high spots in this area that will allow the wheel to not kick when it makes contact with the axle head which in turn will help keep the car tracking straighter. 2. By truing the outer hub, this will allow the builder to accurately mount the wheel in reverse on the Pro Mandrel and get accurate results like using the Pro Hub Tool. This way the builder can perform any wheel performance tasks they prefer. Instruction included. Note:The Pro-Outer Hub Shaver is intended for use on BSA and PineCar wheels. It is not intended for use on wheels by other manufacturers.