is a buttonhole attachment for a straight stitch machine. remove the regular foot and the screw holding it in place. a larger screw is required to hold the attachment in place, the fork is slipped onto the screw. the feed dogs must be covered with a smooth plate. raise the attachment, place the fabric between the attachment and the smooth plate. lower the attachment. size of the buttonhole can be controlled by the wing nuts on the back of the attachment. when it is in motion, do not hold onto the fabric. the attachment moves the fabric back and forth, creating a zigzag stitch.