This thread winder is designed to be used with card bobbins and stranded embroidery cottons. There is a little peg that corresponds to the hole in the cardboard bobbins, which will then hold to bobbin while you wind the thread onto it.
However - these also make a terrific, inexpensive cord twister. Carefully screw a cuphook into the plastic after removing the peg (shown in the second image) and you now have a way to twist a length of cord. Do not remove the cuphook - to do so will probably break the plastic, instead have one for bobbins and one for twisting. If you prefer not to use the cuphook, threads can be tied through the peg hole.
We'll even include a cuphook!