High Quality Hinged Presser Foot with Guide for Industrial Single Needle Machine. Mainly used for edge stitching or top stitching on garments. These presser feet are offer in 9 different sizes and have guides on Right Or Left Side. The indicates the distance between the sewing need to the sewing guide on the right or left depending on which you choose. Choosing the side for guides: The guides are numbered by R's and L's at the end of the size. The ones with "R" on them guide will be right side as if you were sitting in front of the machine, and the opposite for "L" left side. (refer to pictures to help you determine which side guide you need)