GraviTrax is the all new STEM track system from Ravensburger! Use your imagination to build superb tracks and set the Gravity Spheres rolling! Zip along! The Zipline connects track sections to overcome long distances and varying elevations. Combine the Zipline with the GraviTrax Starter Set (sold separately) for spectacular gliding action. How far will your marbles go when connected across the tracks via Zipline?