STARRETT Vernier Caliper Features 2ZUF3: Vernier calipers have a fixed jaw paired with a sliding jaw that moves along a graduated scale to take inside and outside measurements. The jaws are used to contact the opposite sides of an object, workpiece, or feature. Operators read the main and vernier scales and add the values together to determine the reading. These calipers require expertise to read correctly. Range / 0 inch to 12 inch; 0 mm to 300 mm Graduations / 0 inch/0 mm (Lower Scale); 12 inch/300 mm (Upper Scale) Accuracy / +/-0.001 inch (0-4 inch), +/-0.0015 inch (4+ inch) Caliper Material / Stainless Steel Dimension Type / Inch/Metric Graduations - Lower Scale / 0 inch/0 mm Graduations - Upper Scale / 12 inch/300 mm Jaw Actuation Type / Slide Jaw Depth / 1-1/2 inch Maximum Measurement - Decimal Inch / 12 inch Maximum Measurement - Fractional Inch / 12 inch Maximum Measurement - mm / 300 mm Measurements / 4-Way Measures Depth / Yes Measures Inside Dimension / Yes Measures Outside Dimension / Yes Measures Step / Yes Minimum Measurement - Decimal Inch / 0 inch Minimum Measurement - Fractional Inch / 0 inch Minimum Measurement - mm / 0 mm Operation Type / Mechanical Case Type / Plastic Finish / Satin Chrome Jaw Shape / Standard Jaw Long Form Calibration Certificate / No With Locking Nut / Yes