The Brown & Sharpe TESA Micro-Etalon 225 Outside Micrometer has a vernier scale in metric units for taking precise outside diameter (OD) measurements, a dial indicator gauge for Go/No-Go (GO/NG) tolerance inspection, a friction drive thimble mechanism for uniform pressure during adjustment, and tungsten carbide faces for wear resistance. The vernier scale on the thimble and sleeve is graduated to 0.0001”, with a satin chrome rust- and glare-resistant finish. The dial indicator gauge is graduated to 0.00005”. The anvil retracts by means of a push-button for quick workpiece insertion or release. The spindle and anvil have flat measuring faces and are carbide-tipped for wear resistance. A spindle lock helps provide secure locking of the measurement position. The micrometer comes with a plastic case for storage. Micrometers are precision measuring instruments that use a calibrated screw to measure small distances. These measurements are translated into large rotations of the screw that are then able to be read from a scale or a dial. Micrometers are typically used in manufacturing, machining, and mechanical engineering. There are three types of micrometer: outside, inside, and depth. Outside micrometers may also be called micrometer calipers, and are used to measure the length, width, or outside diameter of an object. Inside micrometers are typically used to measure interior diameter, as in a hole. Depth micrometers measure the height, or depth, of any shape that has a step, groove, or slot. Brown & Sharpe manufactures precision measuring equipment and metrology hand tools. The company, founded in 1833, played a key role in setting industrial standards in the United States. Brown & Sharpe was acquired by Hexagon Metrology in 2001, and is headquartered in North Kingstown, RI.