Manufactured of high quality aluminum alloy, corrosion resistant and durable, not easy to break. Features metric and imperial measurements with clear graduation, embossed imperial graduations and common rafter conversion table, the speed squares is convenient for measuring and read. Its thick edge can be used directly with the saw against the square for cross cuts or angled cuts using the etched protractor scale, let you quickly and accurately mark your cut lines on your stringers. The triangle metric ruler can be used as a protractor, miter, line scriber, saw guide and tri/meter square, framing square and a ruler, ideal for all building and remodeling projects. Metric system(300mm),suitable for all building and remodeling projects, also hobbyists, home builders, manufacturers and artists.