Building it is half the fun. Then you get to play with it. Kit comes with everything you need to construct a working roller coaster with mechanical gears. To let the marbles run, turn the hand crank. Includes 233 laser-cut wood pieces, sandpaper, nuts, glue, and 10 metal marbles. Finished coaster about 10"w x 9"h x 6 ½"d. Ages 14 and up.