The Faithfull Depth Gauge is a versatile tool allowing the angle and depth to be measured simultaneously. The protractor features deep etched graduations 0 - 180° in opposite directions permitting the reading of both the direct and supplementary angles. The rule is graduated in both imperial and metric dimensions up to 150mm (6in) and a knurled thumb nut allows the rule to be locked at the chosen angle. Blade Length: 150mm (6in). Graduations: 0.5mm or 64ths.