This Del Rey™ digital caliper delivers excellent accuracy and is built to last; it features a hardened, stainless steel casing marked to use as a ruler when needed, a conversion chart on the reverse side, and an easy-to-read LCD display. The zero setting may be set at any measurement, making easy work of relative measurements. The display and ruler measure in either inches (display in decimal or fraction format) or millimeters. It's powered by one 1.5-volt button cell battery (LR44, included; replacement batteries available). A protective cover is included.