Accessories. Recommended age from 8 years. Number of pieces: 17. Made of plastic. Includes more balls for even more marble run fun. Plan, test, and realize action-packed track layouts. This set contains not only more balls for even greater marble run enjoyment but also cool storage boxes for existing GraviTrax balls. The Accessory Ball Box is a must-have for all GraviTrax fans. The four boxes are designed in the cool style of the GraviTrax height stones and come in green, gray, and white. Two of the boxes are already filled with a total of 12 silver and colorful GraviTrax balls to get the track action rolling. The other two boxes serve as ideal storage for existing balls. Ravensburger. Established for decades in children's rooms in Germany and around the world, Ravensburger is the leading provider of puzzles, games, and activity products in Europe, as well as children's and youth books in the German-speaking region. 85% of the products are manufactured in Europe and are sold worldwide from there. The Ravensburger publishing house was founded in 1883. A year later, in 1884, the Ravensburger game publishing house was established. It celebrated its first milestone with the best-selling game "memory." Since 2009, the company has also focused on new technologies with the founding of its subsidiary Ravensburger Digital GmbH. It combines the classic gaming world with intelligent electronics, enabling interactive learning.