Fowler 52-520-460 premium IP54 shockproof whiteface Dial Indicator has an American Gage Design (AGD) Group 2, 2-1/4" dial face with a continuous dial, a 0-1" measuring range, 0.001" graduations, a revolution counter, and tolerance markers, and is designed to measure surface variations in fractions of an inch. The 0-100 continuous dial with revolution counter has a total measuring range of 0-1” with each revolution equal to 0.1". This premium indicator includes both center lug back and flat back and has sealed plunger, dust cap, bezel lock and black plate. The carbide ball contact point provides durability and long life. This 525204600 dial indicator has a shockproof ultra smooth gearing, and 4-48 (3/8” mounting stem) contact point. It includes NIST certificate of calibration. This product has full 1 year warranty offered by Fowler High Precision, an American company. If you experience any problem contact Fowler directly for warranty claims. Dial readings with two digits, 0-100 for example, indicate the dial has a continuous dial. Balanced dials are used for reading the difference from a specific surface reference point. Continuous dials are used for direct readings and usually have a larger measurement range than balanced dials. Dial indicators are also called dial gauges, probes, and electronic indicators. These precision instruments measure small linear distances and object sizes. The dial magnifies the measurement so that it can be easily read by the human eye. Frequently used in manufacturing, laboratories, and other industrial or mechanical fields, dial indicators are used anywhere a small measurement must be found and recorded or transferred, such as checking the variation in tolerance of a work piece. Standard dial indicators measure the displacement along the axis of the indicator. Dial test indicators are very similar to dial indicators, except that the axis of measurement is perpendicular to the axis of the indicator.