Safecracker 40 Puzzle

A fantastic and unique puzzle based on a 1911 design from England. Consisting of a base ring and 4 rings that rotate on top, the object is to get each of the 16 columns of numbers to add to 40 at the same time. Can you find the combination? Great fun and quite challenging! Made from beautiful maple and cherry wood. (Note this puzzle does not actually open or allow for space to hide something.)