Get started building your own marble runs with this Quadrilla beginner's set. Drop two marbles into the top block and watch as they race each other down different paths to the bottom. Which one will win? Includes nine distributor blocks, a spiral twist plus a windmill spinner that turns as the marbles pass by. Helps to develop spatial thinking and an understanding of Science, Technology, Engineering and Mathematics (STEM) principles. Praised by the Wall Street Journal as the perfect toy for teaching children how to code. Compatible with all Hape Quadrilla sets. For ages four and over.