The Starrett C183 Steel Protractor is a durable tool that can help you in your work. It has double graduations for greater accuracy and precision. This manual-reading protractor features double graduations, which means you will be able to take measurements more accurately. Made of steel, the durable product has a blade size of 1/2 in. and an overall length of 6 in. The head length is 3 in., while the blade length is 6 in.. The accuracy of this Starrett protractor is +/-0.5 degrees, with repeatability at 1/2 degrees. If you are looking for a high quality angle, pitch, and slope locator, then the Starrett C183 Steel Protractor is what you need.