Gravitrax - Starter Set RaceGraviTrax is an interactive marble track system for boys and girls aged 8 and up: With GraviTrax, children not only build simple marble runs, but create entire marble run worlds. With 180 building elements and action stones, such as the Jumper and Magnetic Cannon, the GraviTrax Starter Set Race creates an exciting race of the marbles the ideal introduction to the world of the interactive marble run, can be combined with all sets. Gift for boys and