I get my Prewound bobbins @ Threatart.com, they have pretty good prices. It takes an "a", they seem to be a little higher than the "L" ,I gets 144 for about $38.00, I get the plastic bobbins, and can re use them on my Decorator"s Choice (Baby Lock), can't use them on my Baby Lock Quest, different size bobbin. I have about 300 on hand, at this point.