Five fun, functional models No batteries required 28-page, full-color experiment manual with step-by-step assembly instructions and scientific explanations Make five awesome machines and learn about the physics of force, motion, and energy. Construct a rubber band-powered race car that zooms across the floor. Build a catapult and launch objects through the air. Set up a launching device that propels a motorcycle across the floor at the push of a lever. Build a balancing dragonfly 555061 and a weathervane to experiment with forces. A 28-page manual guides your 555061 building and experiments with step-by-step illustrated instructions.