This interlocking puzzle consists of twelve identical notched rods.
Once the puzzle has been disassembled, you will see why it is called Devil's Friend...
It is a very difficult puzzle requiring advanced burr puzzle solving methods, even though all pieces are identical.
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 notches arrangements reveal themselves.
