The Westalee Design 6 Point Crosshair Ruler is for marking 3 (120°) or 6 (60°) or 12 (30°) or 24 (15°) reference lines, great for Hexagon Quilt patterns. The 8.5″ size allows you to mark up to 8″ blocks. Click here to watch a short video on how to use the crosshair ruler