Sailrite Professional Zipper Foot Set. This would be referred to as a "left" zipper foot. The needle is exposed on the right. These feet have been specially modified to fit Sailrite’s Professional Sewing Machine. A shim washer may be required (included). Position the washer between the outside foot and the presser foot bar to which it attaches. Install the outside foot so that it is as high as possible. The inner foot should be adjusted vertically so that there is equal clearance under each foot during machine operation when the presser feet are down. Typically this means setting the inner foot so that the attachment screw is high in the slot of the foot.