I bought one of those because it looked like it would crimp stove pipe to help the pieces fit together. (I still think it would and I intend to try it next time.) Then I learned that the ones HVAC guys use for stove pipe/sheet metal duct work have multiple jaws.(like 3 on one side, 4 on the other.)
I was passing the kitchen counter;bath tile area in a home store and they had a tool like that to break the tile after its scored. . . .
So that is what it is.