NUTCASE is a deceptively simple cast metal puzzle by legendary puzzlemaker Hanayama. If you're not planning to try it yourself, here's how to solve it.
The goal is simple: to take apart the bolt and remove the nuts and then put it all back together again. Easier said than done! These are pretty good gifts that don't cost a lot, too.
• Solving The IMPOSSIBLE Nut & Bolt Puzzle!! (YouTube / Chris Ramsay)