Calipers are essential precision measuring tools used in manufacturing environments to accurately measure external diameter, internal diameter, thickness, and depth of components. These fundamental measuring instruments are indispensable for dimensional inspection of machined parts, quality control, and product inspection, available in digital, dial, and vernier types. Used for dimensional verification in metal processing, resin molding, and assembly operations, with typical measurement accuracy of 0.02mm to 0.01mm. Features wider measurement range than micrometers and capability to measure internal diameters and step heights that are difficult to measure with rulers or tape measures.