Basic dimensional measuring instrument for precision measurement of outer diameter, inner diameter, thickness, and depth of parts in manufacturing sites. Features main jaw and auxiliary jaw structure enabling high-precision measurement in 0.02mm to 0.05mm increments. Widely used for quality inspection of machined parts, dimensional verification of molds, wear measurement of cutting tools, and tolerance management of assembly parts. Available in analog, digital, and dial types with measurement ranges from 100mm to 2000mm. Most versatile dimensional measuring instrument in manufacturing industry with different measurement methods and applications compared to micrometers and height gauges.