This German-crafted magnifier has the finest optics and the most distortion-free flat-field lenses available to the police market today. An independent study by the Science & Practices Committee of the California State Division of the International Association of Identification rated this magnifier the best overall of seven top models tested. It rated the highest in center sharpness, overall sharpness, brightness, contrast, color correction, magnification and ease of handling. The view is crystal clear and in sharp focus across the entire field. Providing generous 4.5 x magnification and with a wide 5.4cm (2.125") diameter opening at the base, This magnifier is simply the best classification magnifier available for fingerprint examination and classification. Finest optics and most distortion free flat-field lens on the market. Adjustable lens housing moves up and down for perfect focus.