CNC gear testers are computer-controlled measuring instruments used to check the precision and quality of gears and other rotating parts. The abbreviation "CNC" stands for "Computerized Numerical Control", which means that the measurements are controlled by a computer and performed automatically. These inspection devices are capable of accurately measuring the geometry, spacing and shape of gears. They can also check surface finish, runout and length tolerances. This information is then shown on a display and can be evaluated to identify any defects or deviations from specifications. CNC gear testers are important for quality control in the production of gears and other rotating parts, as they enable fast, precise and automated inspection. This allows errors to be detected and corrected at an early stage, resulting in higher quality and productivity.