Optical instruments and microscopes used in quality control, inspection, and research and development in manufacturing. Includes stereoscopic microscopes, metallurgical microscopes, measuring microscopes, digital microscopes, magnifiers, loupes, optical measuring instruments, and image measurement systems. Used for dimensional measurement of parts, surface observation, material structure analysis, foreign matter inspection, and quality verification. Targets optical observation and measurement equipment essential for factory inspection processes and laboratory analytical work, excluding general safety protective equipment and basic measuring tools.