Singer Overlock Spreader for 14SH and 14U Overlockers
Used on selected Singer overlockers to sew with only two threads.
The spreader or often called an "overlock finger" and is used for many specialist 2-thread stitches using only 1-needles and 2-threads.
One of our images shows the spreader being used on a Singer overlocker. It clips into place on the top looper and guides thread to allow you to use only one needle.