Great for Beginning Robot Builders The engineering genius behind this well-designed machine enables it to get back up on its "feet" whenever it tumbles and then speed away on its two cyclonic wheels. The easy-to-assemble kit only employs one worm gear and less than 20 parts, and in the process engages learning about gear structure, battery wiring, switches, motors and the principles of Ohm's law. Requires 1 "AA" battery and double-sided adhesive tape (not included). Size: 110mm W x 103mm H x 103mm D. Appropriate for Grades 4+