Model:  530-312 (0 to 6"/ 150mm) -Metric/Inch dual scale -Lower Scale Graduation of 0.02mm,  -Upper Scale Graduation of .001" -accuracy of +/- 0.03mm. -High Accuracy model. Features a small face angle of 14 degrees which provides easy reading. -Measures Outside Diameter, Inside Diameter, depth and steps. -Furnished in Satin Stainless Steel with easy reading graduations. -Equipped with a lock screw for holding the sliding jaw position allowing the user to get easy measurements.