An extra Bernina rotary hook bobbin case is always handy for doing bobbin work with thicker threads and for embroidering. You can adjust the tension freely to suit your application while keeping your original Bernina rotary hook bobbin case set for regular sewing.
This bobbin case is for Bernina models 450, 435, 180, 185, 1630, 1001 and 1000 only. It has a 9mm opening to accomodate models with both 5mm and 9mm stitch widths.
Why You Need a Second Bobbin Case