Your child can build an atomically cool coaster with dueling action with this play set. With the K’NEX Atomic Coaster Building Set they can use more than 850 K’NEX pieces to create a thrilling roller coaster building experience. Two dueling cars twist, turn and dive as they race through more than 37′ of track. The K’NEX Coaster builds over 4′ tall and includes a motorized chain lift. Give your child’s mind a challenge. With the K’NEX Roller Coaster, your child can construct two different tracks at once and experience the thrill of watching them race against each other in separate courses. Watch your child experience the pride of having built something so intricate. It makes for an exciting gift that can expand the imagination of a child, and it is sure to provide hours of fun.