The GraviTrax Extension Skytrax opens up the possibilities in your GraviTrax universe. Santorini offers spectacular building fun with the functions. The Skytrax extension includes the innovative Santorini bricks with exciting functions: Drop balls through the bricks, catch them and connect them to form bridges. The slides ensure that the ball races around the majestic towers with momentum and action. Combined with any GraviTrax starter set, this expansion brings even more variety and ball fun to the GraviTrax universe. How much further and more spectacular can the ball roll with these elements? With GraviTrax, children, teenagers and adults don't just build simple marble runs. They create unique marble run worlds. The free design of the marble runs and the exploration of the rolling behaviour of the marbles sharpens their understanding of science and allows them to experience gravity at first hand.