The CDX Cyclone is the most advanced Lego compatible roller coaster model available. With over 900 precision molded pieces, the Cyclone is both fun to build and exciting to play with. The kit assembles into a large 4' long model that can be easily modified into different designs. Functioning just like a real roller coaster, a chain pulls the train to the top of the hill where gravity takes over from there. The Cyclone was designed by a real roller coaster engineer to mimic the scale and functionality of a nostalgic wooden roller coaster.