The National Geographic Glow in the Dark Marble Run is a phenomenal construction activity kit for kids! This 250-piece set has everything you need to create incredible marble runs that will have your glowing marbles racing toward the finish line! This Kit Includes: 50 Glow in the Dark Marbles, 1 UV keychain light to help your marbles glow brighter, longer, 135 Smooth-run tube pieces, 55 Action pieces that fit securely together, so you can be sure that your marble run maze won’t fall apart when you play, 10 sturdy bases to build a stable structurem 1 Storage Bag, 1 Learning Guide with Instructions, Configure the pieces in any design you’d like – the possibilities are endless! A detailed learning guide has lots of information about the physics of motion and gravity, so you can learn while you play! And when you’re all done, a convenient mesh storage bag is included so you can keep all your marble run pieces stored together. National Geographic Toys makes the highest quality hands-on science toys, and all products are backed by exceptional service. About the National Geographic Society: With a mission to inspire people to care about the planet, the National Geographic Society is one of the world’s largest nonprofit scientific and educational organizations.