L2003/L2020/L2030 series upright metallurgical microscopes are suitable to observe surfaces of opaque object or transparent object. They are equipped with excellent logne working distance plan achromatic objectives and wide field eyepieces, provited excellent optical quilatity and operation performance. Enable selection of the illumination mode, such as reflected, transmitted and reflected light working independently or synchronously, achieved the request of different sample checking. They are the ideal instruments in research work for metallography, mineralogy, precision engineering, electronics, etc.