Amazon's Gold PLUS Digital Caliper has an accuracy of 0.001"/0.02mm with a measurement range of up to 6"/150mm. The digital LCD display, with hold feature, displays either in inch or metric units for added versatility when measuring and either absolute or incremental measurement modes. These measuring calipers have a zero setting and absolute and incremental modes for taking intermediate or differential measurements. The knurled lock screw holds the sliding jaw in position when required. This caliper is used for measuring inside dimensions (ID), outside dimensions (OD), depths, and steps. Digital calipers are measuring instruments commonly used during manufacturing to provide precise dimensional measurements. A pair of jaws attached to a long beam, with a marked scale, is used to take inside, outside, and step measurements. In addition, digital calipers can take differential measurements that are used to determine the difference in measurements between two objects by zeroing the display at any point along the scale. This product has a full 1-year warranty.