The Omnigrid Square Ruler is perfect for cutting squares from strips, cutting strip sets into segments, cutting pieces for quilts, trimming foundation piecing, and cutting diamonds, triangles and hexagons. Its marked for left and right handed use. In general, Omnigrid square rulers are used for secondary cutting of strips, and to square up finished quilt blocks Use with a rotary cutter or a straight-edge blade Diagonal angle line Edge markings for accurate measuring Laser cut edges for smooth, deep cutting Patented double-sight lines that show up on light and dark fabrics Heavy-duty durable acrylic material Left- and right-hand numbering and angle system