Little engineers can create their own rovers, choppers, or crazy rolling contraptions with the Rover Gears building kit. Open-ended building allows for almost endless creations. Kids snap the gear pieces together and send their rover rolling—an engaging way to build STEM skills, motor skills, and critical thinking. Works with all Gears! sets. Size: 22.9 x 23.1 x 7.1 cm. Ages 4+.