Fowler 52-030-012 Stainless Steel Inch/Metric Reading Dial Caliper, 12" Maximum Measuring, 0.001" Graduation Interval Dial graduations of 0.001" and 0.02mm, with one revolution equivalent to 0.100" and 2mm Hardened stainless steel construction for corrosion resistance and long life Dial face shows readings in both standard and metric units Knurled lock screw holds the sliding jaw in position to help ensure a consistent measurement Covered rack to prevent dirt and debris from clogging the gear, and to help prevent measurement errors