I found this in the boxes of accessories in a 201-2 I bought a few months ago. It has 2 sets of accessories (at least) that include some with featherweight numbers. This has no numbers on it. I almost think it's a feed dog cover for a featherweight, but I looked that up and they don't look like this. Unless, of course, it's a homemade one. I don't have a featherweight to try it on.