With the GraviTax Push expansion, children aged 8 and up can experience even more action in their individual marble runs The three popular action pieces Hammer, Volcano and TipTube together in one set. Combined with a starter set, this expansion provides the impetus for even more action on the track. The Push extension makes it easy to experience how impulses are passed on in the track. Three GraviTrax classics in one set for concentrated action in one fell swoop. With the three action bricks Hammer, TipTube and Volcano, it is possible to build longer tracks with more energy. With GraviTrax, building fun has free rein. The GraviTrax marble run system can be expanded infinitely, which guarantees unlimited building and playing fun. By freely designing the marble run and exploring the rolling and flying behavior of the marbles, an understanding of science is enhanced and gravity can be experienced first-hand. The STEM symbol on our products indicates a category of games that allow you to experience science through play. STEM (Science, Technology, Engineering, Mathematics) corresponds to the German MINT (Mathematics, Informatics, Natural Science, Technology).