The Mitutoyo 201 series dial snap gauge is sized in inch units for Go/No Go (Go/NG) inspection of diameters of cylinders and shafts, to verify the workpiece is within tolerance limits. It can be fitted with a dial indicator that has a 3/8€ stem diameter to measure deviation from a preset minimum tolerance (sold separately).

The anvils of the snap gauge are made of carbide to help resist wear, and their front edges are chamfered to ease insertion of a workpiece between them for inspection. One anvil can be repositioned by turns of a knurled spindle up to 1€ of positioning range, and a knurled, nut-type spindle lock provides secure locking of the measurement position. The fixed anvil has a retraction stroke to 0.078€.

Snap gauges, also called gages, are precision measuring instruments used to verify that the dimension of a workpiece matches or falls within predefined tolerances. The instrument provides quick limit, also called Go/No Go (Go/NG), inspection by testing the fit of a workpiece to pass between an adjustable opening between anvils. A snap gauge may include a dial or electronic indicator to measure the deviation from the preset dimension. Snap gauges are typically used in manufacturing, machining, and mechanical engineering.

Mitutoyo manufactures precision measuring tools, metrology equipment, and systems. The company was founded in Tokyo in 1934 and formed Mitutoyo America Corporation in 1963, which is headquartered in Aurora, IL.