The Mitutoyo 468 series Digimatic Holtest LCD inside micrometer has three-point contacts for self-centering measurement of the inside dimension (ID) of bores, and a digital single-value LCD readout that displays in metric units with resolution to 0.001mm. It also has Statistical Process Control (SPC) data output to transmit results to a computer or external device through an interface cable (sold separately).The micrometer’s electronic microprocessor can hold measurements at any position, convert to absolute value, set a temporary zero position, and return to a true zero reading. An automatic off function helps preserve battery life when the unit is not in use. The electronics housing has an Ingress Protection 65 (IP65) rating, which means that components are resistant to penetration by dust and debris, and resistant to penetration by liquids and coolant up to the force of a low-pressure (to 30 kilonewtons/meter-squared) water jet. The measuring faces are made of hardened steel are TiN-coated for wear resistance. The micrometer includes, and is powered by, a single SR44 silver oxide battery, and comes with a fitted 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.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.