Big Horn 19203 Digital Stainless Steel Caliper, 12" Caliper Range: 0 to 12 inches / 0 to 300 mm; Lightweight Jumbo LCD Display; Comes with carrying case and extra battery External, internal, step and depth measurements; Machine-grooved thumb roll mechanism and position lock for sure adjustment Resolution 0.001";Hardened stainless steel shaft with depth measurement probe Switch between inch/millimeter with ease; On-off switch with auto off