The Dynamic Tuning Set is ideal for making extensions to all fischertechnik marble tracks (Dynamic M, L, XL and Rolling Action) to make them even bigger and faster with extra obstacles and add-on elements. Many special parts such as 90 degree bends, crossovers, catch funnels, short and long flex rails promise even more excitement. The fischertechnik Dynamic Tuning Set gives free rein to the imagination of young marble track engineers.