I have an older Viking and it only uses Viking bobbins, they have a slight contour to them and the ones I have are all plastic. It has to be specific to your machine, not "any" Viking bobbin will work. Try a Viking dealer, I have only been able to find them at trade shows. I just got back from the Houston festival and tried to get some from the Viking dealers there but they didn't bring any with them for the older machines. Good luck!