The Fowler 52-646-100-0 Dial Bore Gage with carbide tipped anvils has a measurement range of 0.7-1.5". Bore gages measure holes or bores in a workpiece and can measure the interior diameter at any depth (within their reach). They are typically calibrated with a setting ring and come in two types: simple and direct measuring, and are used with a caliper to transfer the hole measurement, while the more complex gages take the measurement directly and display it through a vernier, dial, or digital display. These gages have two-point contacts that are better at measuring ovality, while three-point contacts measure lobing or triangular form error. Pistol-grip bore gages are used for fast, single-handed operation with repeatable results from one operator to another. Fowler, an American company, manufactures premium inspection and measurement instruments like electronic indicators, calipers, bore gages, and micrometers. The company, founded in 1946, is headquartered in Canton, MA.