Expansion Set The Lifter Expansion Set takes your marble run experience to a whole new level with over 25 additional elements. Once the marble reaches the bottom, raise it up to 3 levels higher using the Lifter accessory: a button-operated elevator. Experiment with additional tracks, height tiles, and one transparent level. Combine with the GraviTrax Starter Set and test your skills to see how long you can keep the marbles rolling.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. Contents: 1x Lift, 7x Gravity Spheres, 1x Clear Level, 8x Large Vertical Tiles, 4x Small Vertical Tiles, 1x Long Rail, 2x Medium Rails, 3x Short Rails