With the hammer, you can accelerate your marble again so that it can roll even longer. Combine the hammer with the GraviTrax Starter Set and add even more action to your tracks. Will you get your marble to the finish? The fun of building knows no bounds. Contents: 1 Action Stone Hammer, 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.