Impossible joint by Wil Strijbos

This is a type of impossible object, so called because there appears to be no way to separate the two pieces. To make the puzzle harder, a magnetic lock is inside and it has to be released before the two metal parts of the puzzle can be separated. Wil Strijbos is a clever puzzle designer and manfacturer from The Netherlands. Because the idea of this puzzle is to take it apart, people interested in mechanical puzzles also classify this as a Take Apart Puzzle.