A truly mesmerizing marble-track experience! Set is made up of hollow stacking cubes and a variety of perfectly flat tracks. The paths cut out of each track widen almost imperceptibly from one end to the other, creating an invisible slope that propels the marbles forward. Watching them go is like magic in slow-mo! Starter set includes 1 catcher, 1 topper, 30 risers, 5 stainless steel marbles, and 6 unique tracks. The 43-piece Starter Set is ideal for an introduction with three guided builds. Ages 8 and up.