The EOTech G45 is a fixed 5X magnifier designed to be used behind a red dot or holographic sight, extending effective range for target identification at distance. Features: Fixed 5X magnification 2.6" eye relief Approximately 4.4deg angle of view Switch-to-Side (STS) QD mount that flips to the side when not in use Adjustable diopter Tool-free adjustments Fog and water resistant Black Mounts on MIL-STD-1913 Picatinny rails via the included Switch-to-Side QD mount and is used behind an EOTech (or other) red dot or holographic sight. Magnifier only; a sight is required for use.