Experiment with marbles. Learn about friction, potential and kinetic energy, weight and spinning forces, centrifugal force and water tension. You will never look at a marble the same way again. Includes an informative Ein-o Guide. Packaged in a handy, durable "Ein-O Lab-Top" case with handle. Case measures approximately 5.5 x 6.5 x 2.5 inches. Ages 6 and above