A great tool for your selection of jewelry feature color: Silver size: 30 x 21mm mirror diameter: 21mm thickness: 6mm material: All high-quality metal, abs plastic, high-quality optical glass lenses. 1 x 30x21mm glass magnifier. Application range: Industrial purpose, circuit board and printing, industry, medicine, gardening, coin, stamp, jewelry, appraisal, education, geography, home and office.