Pinewood Derby Axle slots for inserting your axle of vehicles the Pro axle inserter guide is available pre cut in pine wood blocks to help you. Pinewood Pros patent pending design is a pre cut slot for you to slide into your interior, one piece axle guide in the block. No extra tools or adjustments are required. It keeps your thumb a small indentation and put it down, the Derby Block blocks to the guide keeps the axle in the slot on the side to turn, push it down and slide the axle in the polarity indicators inside the compartment. Axle Inserter Guide features a built-in wheel spacer is not so you can ensure the ideal spacing to make wheels dont bind or wobble. Perfect spacing and a straight insert, you can create a faster vehicle.