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 (Not Included). Includes 50 pine planks, idea book and 2 balls. Ages 7 & up.