The Fowler 54-101-200-1 Xtra-Value Cal digital caliper has an accuracy of 0.0016"/0.04mm with 0.0005"/0.01mm resolution, and it has a hardened stainless steel frame. The digital single-value readout LCD shows inch and metric units for versatility when measuring. This caliper has a floating zero setting with 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), depth, and step. It comes with a fitted case for storage. Fowler, an American company, manufactures inspection and measuring instruments such as electronic indicators, calipers, bore gages, and micrometers. The company, founded in 1946, is headquartered in Newton, MA.