Mix up the marbles’ journey with the Mixer. Add some surprise to your tracks by sending up to three marbles into the Mixer and see which sides they exit from. Combine this accessory with any GraviTrax® Starter Set. GraviTrax is a modular interactive track system where you can design and build your own marble runs. This STEM toy for children ages 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.