This puzzle is made from sturdy hard plastic pieces that more or less click together. It keeps it shape well as it is built with only the final piece or two being rather fiddly to fit. The picture from which to work is rather small and not as helpful as it might be. However as all the pieces are numbered (from 1 to 240) you can check whether you have the right one before piecing it together. This said, we did manage to put a large number of pieces together in the wrong place without noticing as the shapes of the pieces are fairly uniform and the puzzle pattern (picture) repeats itself. The finished puzzle is smaller than we expcted and makes a ball of about six inches diameter. All in all a different, fun and ultimately very satisfying puzzle.