Create intricate, tunnels, towers, ramps and chutes with this interactive STEM tool! No glue, no connectors, just simple stacking and the laws of gravity. Each Contraptions construction set comes with 200 high-precision KEVA planks and two specially designed bouncy balls that are lightweight for maximum action! The detailed guide book shows you the steps needed to build numerous clever builds and is loaded with dozens of full-color photos, ideas and inventing tips. Learn the basics of physics and engineering. Strengthens analytical skills, resilience and creativity. Guide book is loaded with instructions, photos, ideas and tips. Simple, high-quality materials for countless hours of fun. Ages 7 and up.