Compact, pocket-size, tricky, 4 piece cast metal puzzle.
Objective: take apart the 4 pieces. There are 2 round discs inside 2 triangular shaped frames.
Re-assembly is equally challenging.
One of over 65 metal brain teasers from Hanayama Puzzles of Japan (and BePuzzled here in the USA)
Level 5 Difficulty (on a scale of 1 to 6 where 6 is most difficult).