A micrometer is regarded to as a subtype of a gauge, and it specifies in exact length estimation. The technological peculiarity of this utility is that it uses a screw-based mechanism to quantify distances that cannot be measured with regular methods. The first known prototype of this tool was created in the 17th century, and it was used in astronomy. Micrometers can be divided into three main types. The 1st type (called depth meter) quantifies the depths of cavities and openings. The 2nd type (inside) measures diameters of openings on an object. The 3rd one (outside) estimates the length of objects, diameters of spheres, etc. Analog micrometers can be somewhat difficult to read, that’s why some devices have digital indicators to prevent possible human error while measuring. Buy micrometers on MegaDepot - and you will surely get a quality product at a low price.