Build a twisting, turning marble run and race incredible glow-in-the-dark marbles!This 50 piece set has 41 construction pieces, 8 marbles, a UV keychain light, and a mesh storage bag. Everything you need!Learn about motion and gravity in the detailed learning guide.Experiment with different marble run builds to make your marbles race faster or slower. The fun never ends!For Ages: 8+WARNING: Choking Hazard, Button Cell Battery Hazardous if Swallowed