With the GraviTrax PRO element Helix, up to six route passes can cross How many balls can the Helix pass in one pass?With the GraviTrax PRO element Helix, up to six route passes can cross If a sphere rolls into the helix, it leaves THE PRO element on a lower plane. So up to six balls can drive the stone at the same time. Combined with any GraviTrax Starter-Set, THE PRO Element Helix in this way brings new momentum and energy into the ball track.GraviTrax is a flexible, interactive ball track system for children aged 8 and over: With GraviTrax, children, young people and adults are not only building simple ball tracks. You create unique ball track worlds. By freely designing the ball tracks and exploring the rolling behavior of the balls, the understanding of science is strengthened and gravity can be experienced at first hand. The GraviTrax Universum contains three exciting lines - CORE, PRO and Power. All GraviTrax lines and products can be combined freely. With innumerable expansions