The Pro-Body tool will improve the speed of your pinewood derby car by: 1.Axle Slot Preparation - For kits with axle slots, the Pro-Body Tool ensures accurate axle positioning by allowing you to drill accurate axle pilot holes into the existing axle slots with a hand drill!. The pilot holes ensure that the axles are mounted square and true on the car. Improved axle mounting accuracy equals greater speed! 2.Axle Hole Drilling - For races which allow axle holes, the Pro-Body tool serves as a guide for drilling accurate axle holes with a hand drill. Again, improved axle mounting accuracy equals greater speed! 3.Axle Hole Re-drilling - For kits with the screw and 3/8" dowel rod axle system, the Pro-Body Tool (Model 5148) allows you to accurately re-drill the axle pilot holes. When using nail-type axles, the Pro-Axle Press and Pro-Body tool work together to make a well-aligned and smooth rolling car.