Get ready for the ultimate building set for aspiring engineers and thrill-seekers: the K’NEX Marble Coaster Run with Motor! This innovative new set allows you to flex your creative muscles and build a fully-functional marble coaster from the ground up. With over 500 pieces and multiple builds, this building set is perfect for all skill levels from beginner to pro. Hook up your coaster to the working motor and watch your creation come to life with exciting movements and chain reactions that you can watch again and again.