Starrett 505A-7 ProSite Protractor Takes error-prone calculations out of miter cuts Upside down or backwards, the reading is always correct Scale shows angle for a miter joint and single cut Saves time and reduces waste Ideal for carpenters, plumbers and all building trades 7-Inch miter saw protractor with two scales-red -Inchmiter cut-Inch scale and black -Inchsingle cut-Inch scale Allows direct transfer of the work angle to the miter saw in 3 steps with no calculations Features durable 1/4-Inch thick aluminum alloy and reflon O-ring for smooth, precise operation 12-Inch version also available to cover 7-Inch long; 1-1/2-Pound; 1-year warranty