If you are wanting to sew straight and need some help then these guides are for you. The Bernina seam guides, with built-in measurements, makes sewing straight lines a breeze. Just slide them into the back of your presser foot, set them to the width you want and off you go. Included is a right side guide and a left side guide. The measurements on the guide are in both inches and centimeters so you can get very precise with your lines.