This compact digital caliper accurately measures ID, OD, and depth; it features lock-down calibration to make it easy to replicate precise measurements. An easy-to-read digital display measures 020mm with 0.01mm accuracy or from 01″ with 0.001″ accuracy. The sturdy gauge is constructed of stainless steel and high-impact nylon for durability and longevity, and it requires one 357 (LR44 or SR44) 1.5-volt button battery; two are included. A protective case is included.