Use this head-mounted magnifier and have both hands free to examine fingerprints or evidence. The adjustable headband conforms to fit all head sizes and hold firmly to your head without moving. The OptiVISOR is lightweight and comfortable when worn for long periods of time. The optical glass prismatic lenses are ground and polished to meet precision optical standards and the lenses are bevel-edged and mounted in an interchangeable plastic frame. Two levels of magnification are available, 2X and 3.5X.