A walking foot, also known as an "even feed" foot, has feed dogs that push the top of the fabric thru the machine along with the bottom, thereby feeding the two together evenly. Better and more consistent fabric movement makes for a better and more consistent stitch.
We guarantee the function on all Singer slant needle machines such as the 400 and 500 series.
If you have a Singer 301 then order our other slant walking foot, QC012219B, which we set up and fit to actual 301 machines to make certain they work correctly. This one will also work on the 400 and 500 series Singers too.