1、RELIABLE MATERIAL: This carpenter square is made of aluminum alloy die casting, which is oxidation resistant, not easy to rusty. Each ruler is thick, with high hardness and not easy to break 2、ACCURATE SCALE: Engraving scale possess high accuracy, to ensure the accuracy of work. This triangular also include a unit conversion table for length and angle to make your work more convenient 3、VERSATILE AND MULTIFUNCTION: Accurate rafter ruler to meet a variety of measurement needs, can measure angles and accurately mark lines, allowing you to draw a variety of geometric shapes 4、CLEAR GRADUATIONS: Include 30cm triangular ruler, with black matte finish to prevent dazzle. Employing etching for the scale, and has a common rafter conversion table on the ruler for clear conversion, providing you with a high level of accuracy and easy readability 5、DELICATE ERGONOMIC DESIGN: Metal square is easy to hold when using and convenient to hung and store when not in use, and the ruler surface is smooth and flat, so that won't hurt your hand when you use 6、EASY TO USE: The tangent line is flat so that you can easily make the ruler flush with the wood, creating a straight or angled line that is proportionate to the wood edge 7、MULTI PURPOSE: The metal rafter square can be used as a protractor, saw guide, woodworking compass, triangular square and frame square. Suitable for woodworking projects