With the Guidecraft Unit Blocks Marble Run Set, kids can create mind-boggling marble mazes with the classically-constructed unit blocks that kids already love. The Unit Blocks Marble Run Set features over 70 pieces of hardwood blocks, which are great for designing cool constructions that also serve as thrilling marble runs! This Unit Blocks Marble Run Set is great because block play not only expands the imagination, improves problem-solving skills and introduces important math concepts, but the marvelous marble tracks that kids can build are simply amazing and educationally-based too! The Guidecraft Unit Blocks Marble Run Set allows kids the freedom to build their own exciting block constructions, or they can follow the included instructions to build thrilling marble run layouts! Includes a wooden storage case that measures 18"Lx13"Wx7"H.