It is actually called a stitch in the ditch foot! It has a guide blade between the toes that sits into the seam and helps part the fabric. The needle lines up with the back of the blade and sews right into the center. I have 2 Kenmore Ultra machines (from 1980) that I work to death. SewClassic.Com is terrific for getting parts to older machines, and I found it on there when I was looking for a darning foot for FMQ. About $14, fast shipping and great service.