GraviTrax is the all new STEM track system from Ravensburger! Use your imagination to build superb tracks and set the gravity spheres rolling! Stop, collect, and release! Round up your marbles with the Tip Tube and set them free again! Combine the Tip Tube with the GraviTrax Starter-Set and create unique action in your track system. How long can you pause your marbles with the Tip Tube?