Pack an extra punch into your next dynamic marble run with the game-changing, radio-signaling “GraviTrax POWER Extension Interaction” set!Ready to automate your marble track fun℃ Check out the “GraviTrax POWER Extension Interaction” Set! Packed with 8 accessories that link via radio signals — you determine if the POWER Trigger signals the POWER Starter, Switch or Lever. Or, use the POWER Controller to be in charge! Watch your marbles get a lift up 7 levels with the POWER Elevator, no reset required! Completely compatible with all GraviTrax sets, players learn basic coding skills as they boost the power of gravity!GraviTrax construction sets are a creative, expandable track system that challenges children to use their imagination to design and build their own marble runs! STEM-friendly concepts build critical thinking and problem-solving skills. Completely open-ended, every GraviTrax set has a boredom-busting variety of play options for hours of fascinating fun. Master the basics, then add expansion sets to propel those metal marbles around the tricked-out track of your dreams!