With the GraviTrax Power Extension Interaction, ball track construction for children from 8 years of age becomes electronic. Electric stones send and receive signals. When the ball rolls through the trigger, it sends a signal – now, you’ve got to react! Build Your Own Ball Track The player determines whether the switch, the dome starter or the action stone lever should react to the signal. Use the controller included with the GraviTrax Power Extension to influence the course of the ball! The electronic elevator brings balls up one level automatically and without a manual reset. Thus, new energy is gained and an almost endless marble run adventure can start.Enjoy Constructive Play The GraviTrax Power Extension is an interactive ball track system for kids from the age of 8. With GraviTrax, children create entire ball track worlds. The construction plans make it easier to get started, with no limits to creativity. By freely designing the ball tracks and exploring the rolling behaviour of the balls, the understanding of science is sharpened and gravity can be experienced up close.STEM Learning and Play The STEM sign on Ravensburger products signals a game category in which science is experienced in a playful way. STEM (Science, Technology, Engineering, Mathematics) corresponds to the German MINT (mathematics, computer science, natural sciences, technology). With various extensions to the GraviTrax Power Extension, children can enlarge their marble runs and design them again and again - long- lasting fun guaranteed.