The Omnigrid 9-1/2" square value pack contains one each of 4 square Omnigrid quilting rulers (2.5", 4.5", 6.5" and 9.5"); each has an extra 1/2" for seam allowances and diagonal angle lines; use them to cut, square and trim blocks. Use with a rotary cutter or straight-edge balde for secondary cutting of strips and to square up finished quilt blocks. Details:ClearSizes: 2.5" x 2.5", 4.5" x 4.5", 6.5" x 6.5" and 9.5" x 9.5"Set of 4 quilter's rulersDiagonal angle line and edge markings for accurate measuringHeavy-duty durable acrylic material with laser cut edges for smooth, deep cuttingDiagonal angle patented double-sight lines that show up on light and dark fabricLeft and right hand numbering and angle system