The interactive marble run system from Ravensburger. Control and program a marble run with a smartphone or tablet? No problem with the GraviTrax POWER Element Connect and the GraviTrax POWER App! Additional POWER elements are required (not included in the set). With the GraviTrax® marble run system, you can discover gravity in a playful way, 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. Control and program a marble run with a smartphone or tablet? No problem with the GraviTrax POWER Element Connect and the GraviTrax POWER App! Additional POWER elements are required (not included in the set). With the GraviTrax® marble run system, you can discover gravity in a playful way, and with various expansions, it can be enlarged for limitless building and playing fun! Add even more speed with the expansion sets. Contents Power Connect element, manual Age 8-99 years packaging 11x11x6cm runs on 2xAAA batteries (excl.)