Knock, knock, knocking on wooden floors this wacky walking ReBot is pieced together from a tennis racket, hammer, and the rear wheels of a tricycle. Fast and easy to build. Demonstrates wheels, slider cranks, and motors in action. Powered by an electric motor. Combine the parts from different ReBotz kits to build your own creations. For Ages 6 and up. WARNING: CHOKING HAZARD – Small Parts. Not for children under 3yrs.