3d printed knob & Bobbin Winder protectors for the New Bernina 990 machines This will greatly help reduce the chances of breaking the stitch width & length knobs & Bobbin Winder on your expensive machines.
The manufactor said that this design was a tricky one. They had to make it with 2 different materials. But it works and fits great! This is why it is more expensive.
3d printed parts may have some imperfections.