These three interlocking rings print in the solved position. Just flex them a little to snap the crossing joints apart. They will quickly fall apart to three joined rings. It's reasonably tricky to put them back, hence the puzzle.
I did not invent this puzzle, but I created this printable version.
I printed this on a Printrbot Metal Simple, and the bridging worked well and they came apart easily. If they are fused, use Customizer to increase the tolerance.