These digital calipers have an extra-large LCD screen for easy readability of measurements. Readings can be displayed in either inches or mm, and the zero button can be used at any time to allow for differences in measurements. The thumb roller and locking screw enable smooth sliding, accurate positioning and fine adjustment. Made from hardened stainless steel, these calipers are built to last. They operate with an included LR44 alkaline button cell battery and feature an auto power-off mechanism that activates after five minutes to help conserve battery life. Supplied in a protective plastic storage case.