GraviTrax: Building Construction A pair of dolphins leap

A pair of dolphins leap through the waves in tandem

so she was groomed to be a chef

featuring classic BRIO magnetic coupling for easy connection to other vehicles

sand timer

GraviTrax: Building Construction A pair of dolphins leapThe Extension Building contains many different basic components to extend the marble run. Combined with any GraviTrax starter set, the Extension Building brings even more variety and ball fun to the GraviTrax universe. How much longer can the ball roll with the new elements? GraviTrax is a flexibly expandable, interactive marble run system for children aged 8 and over: With GraviTrax, children, teenagers and adults don't just build simple marble runs.