4 years & up. Build your course and get the ball rolling! The Basic Building Box features two base plates, lots of run elements, and building blocks to design your one-of-a-kind track. With endless possibilities, assemble your run and watch the marbles race to the end. This marble run promotes fine motor skills, logical thought, and creativity. Included: 50 Run Elements, 67 Blocks, 2 Base Plates, 4 Marbles, and a Booklet.