Mitutoyo 500-474 Digital Calipers, Solar Powered, Inch/Metric, for Inside, Outside and Step Measurements, Stainless Steel, 0"/0mm-6"/150mm Range, +/-0.001"/0.01mm Accuracy, 0.0005"/0.01mm Resolution Hardened stainless steel construction for protection of caliper components Solar-powered for continued use without battery replacement Hard-coated solar panels for increased durability in energy storage solar cells and safe operation Four-way measurement capability for multiple applications: outside diameter (OD), inside diameter (ID), depth, and step Digital, single-value readout LCD display in inch or metric units for readability