The paper bobbins, as mentioned earlier, are prewound bobbins, and they are real timesavers. Is there a size like L or M marked on the bobbins? I have not looked lately, but Superiorthreads.com may still have a chart showing which sewing machines will accept them. If not, then try one out in your machine. If it works, great! If not, they can be rewound onto your bobbins.