If the handle looks like this, you gotta call 'em "turnscrews" but that sure is a screwdriver handle. Those handles are comfortable; you can press down hard without digging a hole in your palm.
The calliper may have been *used* as an advertising piece, but it was made as a pocket calliper and sold commercially. I've had a couple over the years. Really useful. Kept using them until I got a steel calliper the same size.