It took me a good while to work this one out. I got it in the fantastic stash from Betty (my friend's relative who had worked as a seamstress), so I knew that it must have had a really good use. I finally worked it out & it is REALLY, REALLY useful - still.
Can you work it out? Those blades are sharp & turn around so that you can select each one. It measures 12cm long & the circle is 5cm wide & the blades are 9mm, 14mm & 18mm wide. Does this help?