Find out how much momentum your marble needs to make it through the loop. Combine the loop with the GraviTrax Starter Set and add even more action to your track layouts. Can you get your marble to the finish line? The fun of building knows no bounds. Contents: 1 action stone loop, 1 long track, 2 medium tracks, 3 short tracks. Warning: Not suitable for children under 3 years due to small parts that may be swallowed.