The INCRA Bend Rule is precisely what you need for layout and measurement along the edge of a board or other work piece. We've put micro-fine marking holes at every scale line to instantly locate your sharp pencil point or scribe exactly on target with zero uncertainty and no eye strain! The 90° shape holds it snugly in place while the two scale surfaces let you mark and measure on the top, edge and corners simultaneously! There are even two vertical end scales for drawing precision parallel lines relative to the edge of your work.