Vintage Singer low shank sewing machine embroidery / darning foot, Simanco part #121094. This foot will fit the 221 Featherweight along with other low shank models as well including the 15, 66, 99, 128, 201, etc. It can be used with a feed dog cover plate in place or with machines that have the ability to drop the feed dogs - Note the elongated thumbscrew slot to allow for height adjustment. Very nice vintage condition, bright and rust free.