The Omnigrid marking ruler trio contains 3 rulers that can be used to quickly and accurately perform a variety of marking tasks when quilting. They come in different lengths, but all 3 have center lines exactly 1/4" from both edges of the rulers, providing an excellent reference line for marking 1/4" sewing lines, adding and checking 1/4" seam allowances and marking 1/4" quilting lines. Item Number: R1264S Package contains three convenient length rulers: 4", 6" and 12" Use a pencil with a fine, sharp point for the most accurate mark Do not use with rotary cutters, knives or other cutting instruments; Rulers are designed for marking use only