Get started building your own marble runs with this Quadrilla beginner's set. Drop two marbles into the top and watch as they race down different paths to the bottom. This marble run construction toy is made with durable wood and non-toxic, water-based paints. Includes 9 distributor blocks, 2 curve rails, a spiral twist, 4 height adjusters, 4 stabilizer rings, 3 accelerators, 2 hole shutters, 30 marbles, a windmill spinner and a universal clamp. The windmill spinner can be attached to any rail with the enclosed clamp. There are endless possibilities for reconfiguring the layout. 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.