It actually looks like someone's attempt to make a tracing wheel from a can opener some time back. The opening on the upper left side and the handle are exactly like part of a can opener I used to have.
I'm surprised that most people say they don't use it anymore. I use it for marking quilt pattern pieces from templates, for marking quilting patterns, and I have a double one that I use to mark quarter inch seams on freezer paper piecing.