I have searched high and low in my sewing machine manuals and on the internet. Also on the Brother website. I can't figure out what this part is for! The good news is I found a walking foot so I am very happy about this. I have two Brother embroidery sewing machines and an Elna Lock serger. I don't know if this part goes to one of my machines. I assumed it came with one of the Brother's but can't be sure. Do any of you know what this part is used for?