When you require exact measuring, you reach for a caliper. But an accurate measurement is meaningless if you can't read it accurately. This caliper takes an essential tool into the 21st century with an extra-large LCD digital readout for exact internal and outside measurements accurate to .001". Instantly converts from SAE or Metric, the display can be zeroed at any point on the scale. Machine-grooved thumb-roll mechanism and position lock for sure adjustment. Hardened stainless steel shaft with depth-measurement probe, precision ground jaws. On-off switch, two long-life batteries included (one extra).