GraviTrax Pro starter set: includes 153 high‑quality components to build advanced vertical marble run designs, for kids aged 8+ to explore creativity, engineering and problem‑solving STEM learning through play: encourages logical thinking, spatial awareness and hands‑on experimentation, Fully compatible with all GraviTrax and GraviTrax Pro sets for endless expansion Experience the power of gravity: Create exciting routes, vertical drops and trick shots, A great Christmas or birthday gift for kids who love science, building and action‑packed play Ravensburger quality: Made from durable, high‑grade materials and tested to strict UK and EU safety standards for worry‑free fun Easy to build, no batteries needed: Includes clear instructions so children can start building within minutes, Expansion sets and accessories are available separately