The Gravitrax Interactive Track System Starter Set by Ravensburger is a gear building set designed for children aged 8 and above. This toy allows kids to create their own interactive track systems using gravity and magnets. With the starter set, kids can build various tracks to create rolling balls and experiment with different gear configurations to achieve unique results. This toy offers hours of fun and creativity for young builders and is a great way to introduce them to the world of engineering and design.