HABA's Ball Track Large Set is made from natural beech wood and includes 6 marbles and a bell. Who would think problem solving could be so much fun? An exciting marble rolling game that is both educational and fun. Hardwood blocks with grooves, and holes are combined in a variety of ways with the end result of 6 marbles ringing the bell to signal success. Helps educates the laws of structural engineering and stimulates spatial thinking. This ball track includes 42 pieces.