Excuse the pun in the title. I've got it to work, but looking around doesn't give much info. I'm assuming it might not be an original Singer part. Does anyone know anything about it?

edit: I should clarify that this box contained accessories mainly for the Singer 66k. Most of them identifiable.

edit2: I've found it on this page (in french) towards the bottom. It is indeed an adjustable hemmer without any further info. Might be a Singer part, might not be. Guessing not since it is not marked with a part number.