Starrett ProSite Aluminum Miter Protractor

5-in-1 combination protractor performs miter cuts, single cuts, compound cut conversion table, protractor and roof pitches. Takes error-prone calculations out of the process of miter cuts. Simply set your saw to the angle that you read. Upside down or backwards, the reading is always correct. This easy-to-use tool has 2 scales. The red scale and arrow show the angle for a miter joint, while the black arrows and scale provide the angle to fit a single workpiece to an angle. It's ideal for carpenters, plumbers, and all building trades that require the measuring and transferring of angles. 12 In. (inch) L.