Up for auction is Impenetrable Knot by Juno
A tough puzzle. In excellent condition. Solved twice by me.
Additional photos on request
From the makers site:
Material: PNG Rosewood and Jarrah
This puzzle requires 11 moves to remove the first piece from the assembled shape and it makes you think that the puzzle is relatively easy considering modern high-level burr puzzle designs. And then once you start playing with the puzzle, it changes the shape dramatically and the configuration of the puzzle pieces is difficult to comprehend.
Many people will somehow succeed to disassemble the puzzle in a rather short time even not knowing which piece moved where and how. Reassembling the puzzle is challenging and you may consider using the aid of a puzzle solving computer program. Here you will face a tough situation because the program will probably say that there is no possible solution though there are four assemblies. Yes, it’s impenetrable to solve the puzzle by ordinary approaches.
The assembled shape of the puzzle is a bit similar to Tangled Clip Burr but it consists of only 6 pieces compared to 12 of Tangled Clip Burr. Three pairs of identical pieces are used for the puzzle but if you look at the pieces carefully, you will notice that the direction of the grain of each paired piece is different. This feature gives higher symmetry for the assembled shape of the puzzle.
It was necessary to use our original plywood to produce the puzzle pieces keeping their durability and strength otherwise the pieces would be easily snapped following the grain. 13.5 mm thick plywood gives quite a volume to the assembled shape and the puzzle will feel solid in your hands.