Extend your run! The Trax Expansion offers over 40 additional elements to extend your track. You'll keep the fun rolling when adding distance to your run. Experiment with the combination of height tiles, tracks and curves. Test yourself to see how long you can keep the marbles rolling before reaching the finish. GraviTrax Starter-Set required Contents: 16x Large Vertical Tiles, 8x Small Vertical Tiles, 7x Curve Tiles, 1x Junction Tile, 1x Long Track, 2x Medium Tracks, 3x Short Tracks, 6x Balls