This precision gauge, which is also called an indicating gauge, consists of a plunger that has gear teeth cut along parts of its length to engage a gear on the indicator needle to provide a visual indication of even very slight variations in the grade of a surface. The gauge, which has a needle that passes around the precise dial, which shows gradations as small as one ten-thousandth of an inch, is tightly clamped to a rigid surface, then the plunger is adjusted to connect with the work which is to be measured. This work is then moved past the plunger, which provides readings of the variations in the surface. When precision measurements, such as centering a piece of work in an independent chuck on a lathe, this gauge is valuable.

Dial indicators are instruments used to accurately measure a small distance. They may also be known as a Dial gauge, Dial Test Indicator (DTI), or as a "clock". They are named so because the measurement results are displayed in a magnified way by means of a dial.