ThisProfessional Miter Protractoreliminates calculations, reduces errors, and provides greater accuracy for a miter cut. It is easy to use by justsimply set your saw to the angleshown on the protractor. Upside down or backward, the reading is always correct.The miter cut arrow and inner scale indicate the exact miter saw setting for anaccurate miter joint every time.The single-cut arrow and outer scale indicate the exact miter saw the setting for fitting a single piece to an angle. This protractor is ideal for carpentry, plumbers, and all building trades that require measuring and transferring angles. Its also invaluable for home use and do-it-yourself. FEATURES SPECIFICATIONS PACKAGE INCLUDES