I have sewing machine guage I use. The distance depends in your needle placement center is used for 1/4 inch foot, i believe right is for the regular foot and left might be 5/8 on regular foot but you have to check the manual. The guage i have is the ideal seam guage. It is purple and i just but my clover seam guide against it to create a guide for my seam allowance. I want to say the markings on the plate are for left needle placement. All brother markings are the same so i would just download a manual of a similar machine