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. Hardened stainless steel shaft with depth-measurement probe, precision ground jaws. Instant-on feature turns digital function on when jaws are moved; auto-off preserves battery life. Uses one common button-cell battery (included); inexpensive and easy to replace.