So I bought a small box of tap wrenches, and it had a dollar general dial caliper in it, as well as this. The guy had no idea what idea it is, and neither do i, he seemed to think it had to do something with machining
The "roller has 2 textures and 3 different sized wheels that thread on.
Ferengi tooth sharpener?
(Actually, I agree with RobotToaster. Seems like a rasp or file for the inside of holes.)