High quality material This square woodworking protractor is made of high quality aluminum. It is rust-proof, has high hardness and good toughness, is lightweight, easy to carry, and can be used for a long time. Precise measurement Our square protractor is laser engraved with metric graduations clear for precise, easy-to-read graduations up to 112 mm (4.41 inches). The woodworking ruler can measure 45 degree or 90 degree angles by simply sliding it. The angle ruler has the functions of measuring, correcting, marking, etc. One ruler is multi-purpose, which can effectively improve woodworking efficiency and save time. Easy to Use The multi-angle measuring ruler is removable. When you screw in the screw, the woodworking ruler becomes a 3D three-dimensional measuring tool. When you don't need it, use the hex wrench to remove the screw, and you can get a square ruler and a triangle miter ruler. Wide Applications The multi-measuring tool angle for carpenters, engineers, handymen, decorators, construction workers, etc. The hollow-shaped design can help you grasp and measure the required materials, suitable for three-dimensional objects, such as wood, metal pipes, marble, etc. This multifunctional woodworking measuring ruler is your indispensable good tool.