This is a bobbin for a Speedy Stitcher.
You will also need a metal axle. I used a piece of wire coathanger, cut to a length so that it fits from the indentation inside the Speedy Stitcher's bobbin compartment to the hole in the bobbin compartment lid. (Note: The stock bobbin had an axle that was much shorter. That doesn't seem like a good idea. Also, a longer axle is better for chucking into a drill for winding.)
I had to drill out the hole to fit the coathanger wire--I should have set more tolerance on that part (you can customize it), but your printer may need less tolerance. And to push the wire through the holes, I spun it on a drill. I glued the two plastic parts together with superglue as I was impatient (JB Weld might have been better).