3-in-1 engineering set: Assemble three cool robots, wind them, and watch them-no batteries required!

This model is driven by a main spring and is mainly an old-fashioned clock.

The model includes a racing car that can travel up to 60 feet, a robot that can walk up to 20 inches, and a countdown timer that can last for 6 minutes.

Understand potential and kinetic energy, and how gears and springs work in different mechanical devices.

Includes a 64-page full-color manual, clear language, simple step-by-step illustrated instructions and scientific explanations