We got some excellent guesses in our recent mystery object post, right up to and including the right answer. Jim, Michael D. Pinho, and Einstein all answered correctly that it is a handheld wire straightening tool.
Manufactured by Du-Bro, you can find these in fishing stores for straightening “wire leaders.” Wire leaders are short lengths of steel wire used at the end of a fishing line when fishing for big fish with sharp teeth that might otherwise bite through your line.
They’re also pretty handy around the shop. We have two different sizes of these, for straightening different gauges of wire.
To use one, you place the wire that you wish to straighten in the center of the three hinged rods and clamp the rods together in your hand. And then, with quite a bit of effort, you pull the wire straight through the center. Doing so forces the wire to bend around the bumps on the rods, straightening out any kinks and twists with surprising effectiveness.