Watch the “GraviTrax Zipline” overcome long distances and varying elevations with spectacular gliding action! Add the “Zipline” to your marble run and watch as your marble triggers the suspended marble to race down the line and whack the marble across the gap and send it on its way. Explore Newton’s Laws of Motion while having a blast! It’s a snap to combine this accessory with any “GraviTrax Starter-Set” to experience the power of gravity and educational fun today!