With this set you expand your marble track system by combining the additional components with your GraviTrax starter set. So you can build ever bigger marble track worlds. How long can you keep the bullets rolling? You break your personal record? There are no limits to building fun. Contents: 2 bottom plates, 1 transparent layer, 8 height blocks large, 4 height blocks small, 2 switches, 1 3 in 1, 1 swivel, 1 target ladder, 4 base blocks, inserts for the base blocks: 2 catchers, 1 free fall, 1 splash, 1 target. Caution: Not suitable for children under 3 years due to swallowable small parts.