Singer Blind Stitch Braider/Braiding Attachment NO. 121614 for Featherweight 221 and 222K.  Will fit any low, vertical shank Singer sewing machine including Singer 15, 66, 99, 127, 128, 201, 306 ………and more!   SIZE:  5/32

It applies braid to the top side of the fabric and is used with braiding designs when  you do not want the stitching to show.  Soutache braid is a favorite frequently used with this braider.