Sometimes you need more tension on the bobbin thread than usual for embroidery, free-motion sewing or free-motion quilting. And that’s why you need the golden-yellow bobbin case. Compatible with the following machines: B700 E, B 720, B 740, B 770 QE, B 790, B 790 PLUS B 500 E, B 535, B 540, B 570 QE, B 590 B 435, B 475 QE, B 485, B 480