Omnigrip Non-Slip Neon Rulers are made especially for quilting, sewing and crafting projects. The forty-five degrees diagonal lines are for triangle cuts, markings for half-squares and quarter-square triangles.Details:Neon green and black10" x 10"1/2" mark for quilting seam allowance45° angle markings for 1/2 square and 1/4 square trianglesLeft- and right-hand numbering and angle systemDouble-sight lines visible on light and dark fabricsAcrylicFor use with rotary cutter or straight-edge blade