Originally Posted by Sewnoma

For 66's, 99's, and anything else that takes a Singer class 66 bobbin, these are the nicest modern bobbins I've found:
http://smile.amazon.com/Bobbin-17222...dp/B0040ZFPBK/

They're steel, well-formed, and they're actually the correct size, unlike modern Singer-brand class 66 bobbins. I tested them in my two 99K's and my 500A and they fit perfectly. I searched around and found a store called Gold Star that sold sewing machine accessories and I thought they might be the same people so ordered some through them, but they are NOT the same as these ones from Amazon. The ones from Amazon are superior. I think they're on par with the vintage bobbins.