The classic interchangeable spiro- tracks let you create your own unique pattern shapes, taking your designs to a whole new and super level! this 13x18x1-1/2 inch package contains two racks, three design pens, six spiro-track end caps, one spiro-track tri-hub, four shaped wheels, eighteen wheels in different sizes, sixteen curved spiro-tracks in different sizes, two rings, spiro-putty, eight straight spiro-tracks, one twenty- four page design guide and jumbo paper and two twenty-five page design pads. Recommended for ages 8 and up.