Made of an optical glass lens with a chrome-plated metal body. Protected when not in use by the swing-out chrome-plated metal cover. The 30x power eye loupe has a focal distance of 1" (26mm) with a 21mm dia lens size. In addition to inspecting precision instruments such as jewelry, stamps, calligraphy, painting, clocks, electronic products, textiles, etc., it can also be used for hand-made needs, an inspection of incisions, or other observation needs. Our jewelry loop magnifier are easy to use, suitable for both amateurs and professionals. They are lightweight and portable, fit in any Purse, Shirt, and Pants Pocket for traveling, camping, and other outdoor.