Officially licensed by the Boy Scouts of America. Gain a competitive edge and make your Pinewood Derby racer run faster. Just add Stick-On Designer Weights! These ultra-safe, 99.99% lead-free weights are sectioned off into different sizes, allowing you to easily fine-tune your car per race regulations. Install by drilling a 0.4 inch dia. hole into your racer, and then use the included double-sided tape to safely secure the weights to your car's chassis. Drill and pliers required.