The interactive marble run system from Ravensburger. With the GraviTrax marble run system, you can build your own marble run world by creatively using the laws of gravity. Use the various building elements to create an action-packed track and guide the marbles to the finish line using magnetism, kinetics, and gravity. With the GraviTrax marble run system, you can playfully discover gravity, and with various expansions, it can be enlarged for limitless building and playing fun! Add even more speed with the expansion sets. The interactive marble run system from Ravensburger. With the GraviTrax® marble run system, you can build your own marble run world by creatively using the laws of gravity. Use the various building elements to create an action-packed track and guide the marbles to the finish line using magnetism, kinetics, and gravity. With the GraviTrax® marble run system, you can playfully discover gravity, and with various expansions, it can be enlarged for limitless building and playing fun! Add even more speed with the expansion sets. Contents: 33 parts: 1 base plate, 2 marbles, 8 large curves, 9 decorative elements, 4 cardboard animals, 3 open base blocks, 6 decoration caps, 1 manual. Age 3+