Launch your marble through your run with the amazingly powerful “GraviTrax Magnetic Cannon”! Simply place two marbles in front of the “Cannon”; when your marble hits, it sends the front marble blasting down the track! A high-powered magnet gives the marble a burst of speed to help extend your run up inclines and down tracks. A great addition to any “GraviTrax Starter-Set”; comes with 3 additional colored marbles. Experience the power of gravity and educational fun today!