The GraviTrax SkyTrax Action Set XXL from Ravensburger expands the GraviTrax marble run system with new Skytrax stones that let marbles pass through, be caught, and link to form bridges. Slides launch marbles in spinning runs around tall towers and inventive action elements create trick-filled courses that spark creativity and problem solving. This large expandable set encourages hands-on experimentation with gravity and engineering and is fully compatible with other GraviTrax lines for endless build and play possibilities.