This interesting tool, found in an older toolbox that’s at least a decade old, has certainly caught some eyes. The part with spokes rotates, and the spokes of different diameters match up to a hole on the opposite side of the device. To give you a sense of its size, there’s a Sharpie marker in the photo for comparison.
The answer to this little mystery? It’s actually a tool for punching holes in leather or similar materials. For instance, it’s something you might use to add extra holes to a leather belt.