lovelyl

I have never gotten vintage bobbin sizes straight in my mind. I know which bobbin fits my 221 and 301, and which fits my 15-91 and 503, but don't know what names they are referred to. Class 66? Class 15? Neither?
I won a goodie bag at my guild and it had a bobbin that looks like it would fit my 15-91, but is shorter. It is the bobbin in the middle of the pics. What does that fit and what is it called? I need a class on vintage bobbins....
Can anyone help me get this straight in my mind (or what is left of it...)😳
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