Approximate Dimensions: 3.25" x 3.25" x 3.25"
This interlocking Burr wooden Puzzle consists of twelve identical notched rods. Once the pieces are disassembled you will see why it is called Devil's Friend. It is a very difficult puzzle requiring advanced burr puzzle solving methods.
The puzzle was created in 1890 by the Austrian-German William Altekruse who even registered a US Patent (#430502). This puzzle is not quite symmetrical visually because the asymmetrical notchs arrangement reveal themselves.