The puzzle has a unique solution in a relatively small number of 91 assemblies, and the computer program Burr Tools showed its level to be 50-18-3-3, the highest number in the Grooved 6 Board Burr series. In the real world, the interlocking of the consisting pieces becomes unstable after around 40 moves from the assembled shape, and it allows a rotational movement shortcut that is theoretically possible. It is yet the largest number ever in the series to release the first piece from the assembled shape.

The size of the puzzle is larger than its ancestors, and the puzzle pieces have the most complex shape in the series. Many pins and grooves have been added to eliminate the possibility of unwanted shortcut solutions. In most cases, we remove sharp edges from the puzzle pieces of our product, but in contrast, it increases the likelihood that the pieces will rotate. We remove the sharp edges of the puzzle pieces on most occasions but in contrast, it can give more chance of rotational movements of the pieces. Rather than saying "only theoretically possible movements are allowed", we decided to add pins and grooves to prevent such unwanted movements.

The difficulty of the puzzle is extremely high, so don't be shy and look at the image below for a hint. You would be proud if you could take apart and reassemble the puzzle without computer aids.

The solution to this puzzle will be supplied upon request by Burr Tools file format.

Size: 89 mm x 89 mm x 89 mm

Number of pieces: 6

Material: PNG Rosewood and Red Gum

Designer: Junichi Yananose (Juno)

Origin: Made in Australia

Ages: 12+