All your measuring and marking needs are met with the Omnigrid Marking Ruler Trio. This set includes three rulers measuring 4”, 6”, and 12” long. Each ruler features center lines placed exactly ¼” from both edges—perfect for marking sewing lines, checking and adding seam allowances, and guiding quilting lines. Please Note: These rulers are designed for marking only and are not intended for use with rotary cutters, knives, or other cutting tools.