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.
Looks kind of like the de-burring tools we used for inside edges and large drill holes when I worked at a machine shop. I bet it’s for removing the edge on inside radiuses for woodworking.