This Presser Foot Alignment Gauge is for setting the accurate presser foot position and height on a Singer Featherweight 221 or 222. The original low shank Singer Presser Foot works best for making adjustments (assuming the foot is in good, balanced condition), but a new, replica presser foot will work as well. This gauge has been confirmed to also work on the following Singer models: 15, 66, 99, 127, 128, 185, 192, and 201. Presser Foot Gauge will not work for the Singer 301 or other slant-shank machines.