K Nex Atomic CoasterBuild an atomically cool coaster with dueling action! Use over 850 K'NEX pieces to create a thrilling roller coaster building experience. 2 dueling cars twist, turn, and dive as they race through over 37 feet of track! The Atomic Coaster builds over 4 feet tall and includes a motorized chain lift. Color coded, easy to follow building instructions are included. Go to www. knex. com to download instructions for a 2nd awesome coaster model.