Young thinkers can design unbelievable ball track structures via simple, stacking planks. No glue, no connectors-just loads of constructive fun! The 50-Plank Set helps kids get things rolling with two balls and an instruction book detailing how to build a "Shooting Gallery," "Turbine," "Step Curve" and more. Fully compatible with our larger, 200-Plank KEVA Contraptions Set.