1: The perfect woodworking layout tool: just press the head to the desired angle, then press the straight line. 2: The blades have the same unique serration. Design line notches are found in the new stainless steel precision woodworking blocks. There are notches every sixteen inches along the blade. Simply place the pencil in the slot and slide the tip to form a perfect parallel line along the edge of the barrel. 3: Woodworking Blade Gauge: The secret lies in a series of precision machined indexing holes and spring-loaded, tight tolerance indexing pins that engage. The pin snaps into place, giving you the confidence to know it"s accurate. 4: Both edges of the blade are laser engraved with 1/32 inch graduations. Increment. The total cumulative error of the scale over the length of the blade is maintained within a tolerance of 0.004". The thin satin stainless steel blade is easy to read and minimizes parallax errors.