The varying difficulty levels, ranging from simple to advanced, allow the set to grow with your child's skills. Multiple Creative Robot Builds: With 438 building parts, kids can build 120+ models such as robots, cars, and other interesting model. Kids will love exploring every possibility with this STEM toy and enjoy the fun of DIY creation and building In-depth Scientific Exploration: This set integrates principles of connecting rod mechanism, gear transmission, sensors, hand crank generator, eccentric mechanisms, circular motion, Inertia & energy, and other scientific concepts.