The Fowler 52-520-199 black-face dial indicator with magnetic base and continuous dial has 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 American Gage Design (AGD) Group 2 dial has a 2-1/4" continuous dial with a reading of 0-100, a revolution counter, a total measuring range of 0-1" and 0.001" graduations, with each revolution equal to 0.1". An adjustable bezel and dial zeros the reading at any location. Tolerance markers allow operators to observe limits at a glance. The magnetic base has an 85lb. pull and the ability to mount test indicators with a 1/4" post. Fine adjustment knobs allow for making micro-adjustments. The base is 2 x 2-11/32 x 1-13/16 inches (H x W x D) and has a V-shape for mounting on round surfaces. (H is height, the vertical distance from lowest to highest point; W is width, the horizontal distance from left to right; D is depth, the horizontal distance from front to back.)The set includes a dial indicator, magnetic base, and fitted storage box. Dial readings with three digits, 0-10-0 for example, signify that the indicator has a balanced dial. 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. Specifications Dial face type and diameter AGD Group 2, 2-1/4" diameter face Dial type and reading Continuous 0-100 Range and graduations 0-1" Graduations 0.001" Revolutions Up to 10 revolutions, each revolution equal to 0.10" Contact point construction Carbide contact point with 0.080" diameter Magnetic base pull 85lb. Base dimensions 2 x 2-11/32 x 1-13/16 inches (H x W x D) Specifications AGD Group 2 H is height, the vertical distance from lowest to highest point; W is width, the horizontal distance from left to right; D is depth, the horizontal distance from front to back.Dial indicators are also called dial gauges, probe, 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 workpiece. 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. Dial and dial test indicators can be analog, with a mechanical dial, or electronic, with a digital display. Some electronic models transfer the data electronically to a computer for recording and potential manipulation.The Fred V. Fowler Company manufactures inspection and measurement instruments such as electronic indicators, calipers, bore gages, and digital scales. The company, founded in 1946, is headquartered in Newton, MA.What’s in the Box? Dial indicator Magnetic base Fitted storage case