No need for a sewing machine to wind your bobbins. Simple bobbin winding at the push of a button with automatic shut-off when the bobbin is full. With the portable, compact bobbin winder, you can take it anywhere. Battery-operated for on-the-go convenience. Ensures you can wind bobbins anytime and anywhere (2 AA batteries not included). For use with class 15 and 15J bobbins.