Cause an explosion with the Volcano, unleashing new energy into your marble run! When a marble rolls into the push button of the Volcano, it triggers an eruption launching up to 3 marbles down the tracks. This accessory also includes 6 additional tracks and must be combined with the GraviTrax Starter Set. GraviTrax is a modular, electronic-free interactive track system where you can design and build your own marble runs. This STEM toy for boys and girls 8 and up, encourages experimenting with gravity, magnetism, and kinetics to propel your marble to the finish. Designed with open play in mind, the concept offers endless possibilities to design a different track every time you play. Expand your builds and add some action with a variety of expansion sets and accessories.