Give your ball fresh momentum with the hammer to make it travel further. Combine the hammer with your gravitrax starter-set for even more action and excitement. Will the hammer get your ball to the finish? With the gravitrax interactive track system and marble run, you can design and build your own race tracks and experiment with gravity, magnetism, and kinetics to propel your ball to the finish. With a variety of tiles, levels, tracks and features, you can control the speed of each ball. The open-ended building concept offers endless possibilities to design a different track every time you play. Add flair and speed to your tracks with expansion sets and action accessories. Gravitrax is a fun STEM toy for boys and girls that comes with over 100 pieces and 18 different construction elements. The gravitrax starter set offers everything you need to begin building your own action-packed track systems. Discover how the laws of physics affect the track your ball takes with curves, crosses, freefalls and even a cannon. Experiment using different heights and angles to control the speed of the ball. The included tasks and construction plans introduce you to the world of gravitrax. Or let your creativity take over and begin constructing your own track designs from scratch.