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 1/4in from both edges of the rulers, providing an excellent reference line for marking 1/4in sewing lines, adding and checking 1/4in seam allowances and marking 1/4in quilting lines Package contains three convenient length rulers: 4in, 6in and 12in. 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 . . Color: Clear. . Made of: Acrylic. . Use: Quilt Marking. . Size: 4in long, 6in long, and 12in long. . Included: 3 Rulers. . .