Thank you all!
BellaBoo - I did wonder if it was just the way they get punched out but then wondered if I was making a bad assumption :-)
Barny - the washers are silicone disks and they fit in the bottom of your machine's bobbin case under the bobbin. They are used for free motion quilting and are supposed to make your bobbin turn more smoothly in the case avoiding broken threads and nasty little nests and knots of thread on the back of your free motion piece. Some people swear by them and won't be without them, including the fabulous Leah Day (love her!) But l did ask this question at the quilt store today. The lady there teaches free motion and has never used them so I guess different strokes for different folks. I'm totally new to FMQ so I thought I'd try the bobbin washers since they were not expensive.