• Explore the world of engineering, gravity, and motion.
• 41 marble run construction pieces and 8 glow-in-the-dark marbles. Together equals the 50-piece count
• Comes with a storage bag to keep all your pieces together
• Compatible with all our other marble run sets so you can build even bigger

This marble run construction set allows kids to build an endless array of marble runs. Pieces connect easily, and the set includes 8 glow-in-the-dark marbles in a variety of colors. A full-color learning guide provides tips on building a great marble run, as well as insight into the science of motion and gravity.