Square Up Ruler, 12-1/2"The OmniCraft 12 1 2" square ruler is used to "square up" quilt blocks, needlework or other crafting mediums. Item Number: RSQ125 It includes measurements from 1" to 12 1 2" Use with a rotary cutter or a straight edge blade Edge markings for accurate measuring and 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