Accurate Measurements: Has an accuracy of 0.001"; perfect caliper for the machinist and household/DIY measurements 4 Measuring Capabilities: These dial calipers can be used to measure inside dimensions (ID), outside dimensions (OD), depth, and step measurements Knurled Lock: Dial calipers feature a knurled lock screw that holds the sliding jaw in position to hold measurement when needed; a thumb-operated fine adjustment roller allows for one-handed use Dial Graduations: The dial hand completes one revolution every 0.1" and features a black dial with 0.001" graduations; the beam has etched with 0.10" graduations with a large, easy-to-read dial Set Includes: black dial caliper along with a fitted case