1The edge ruler can provide unparalleled accuracy for your panel layout work, just press the head to the desired angle,and then press the straight line. 2Head of woodworking ruler can be adjusted between 0 and 70, it is firmly locked every 5 (plus 221/2and 671/2), accurate reference angle and length. 3The surface has laser scales, which is clear and intuitive, easy to read, and minimizes the parallax error, so you can use it more conveniently. 4Easy to use and operate, just put the pencil in the notch and slide the tip of the pen along the edge of the barrel to form a perfect parallel line. 5Both edges of the ruler blade are engraved with a 1/32 inch scale, and the total cumulative error of the scale in the length is kept within a tolerance of 0.004in. 6Suitable for engineering, angle measuret, student drawing, architectural design, length measuret, and perfect for students, carpenters, architects and designers.