The pinewood derby is a racing event for Cub Scouts in the Boy Scouts of America. Cub Scouts, with the help of parents, build their own cars from wood, usually from kits containing a block of pine, plastic wheels, and metal axles. With the popularity of the pinewood derby, other organizations have developed similar events, and a small industry has developed to provide tracks, timers, scales, trophies, ribbons, and other products. Similar Cub Scouting events include the raingutter regatta with boats and the space derby using rubber band-powered rockets.