1、Small Error: Aluminum alloy right angle scribing squares adopts high accuracy laser scale, which is accurate and easy to read, with small error 2、Aluminum Alloy: The whole body is made of aluminum alloy, the appearance is anodized, high hardness, and very durable 3、High Accuracy: There is marked hole design in the ruler, the hole position and the diameter of the hole are accurate to 1mm, convenient for marking and measuring the length and improving the accuracy 4、4 Hole Design: The handle adopts 4 hole design, which is more ergonomic, easier to grasp the tool, and improves the overall appearance 5、Multi Function: Aluminum alloy right angle scribing ruler can draw circles, scribe lines, draw hinge holes, measure angles and other functions in all 1 x Aluminum Framing Woodworking Squares1 x Wrench1 x User Manual Item Type: Aluminum Framing Woodworking SquaresMaterial: Aluminum AlloyMetric Scale: Approx. 300mm / 11.81inBase Aperture: Approx. 20mm / 0.80inBase Length: Approx. 180mm / 7.10inArc Diameter: Inner Diameter Approx. 40mm / 1.57in, Outer Diameter Approx. 60mm / 2.36in