The Trijicon SRS (Sealed Reflex Sight) is a uniquely designed MIL-spec rugged, parallax free, reflex sight which incorporates a larger aperture for maximum situational awareness in a shorter body. The illuminated 1.75 MOA red dot with 10 brightness settings (3 NVG compatible) is powered by a single AA battery assisted by a solar cell to extend battery life. The snag free button pads make brightness adjustments easy and eliminate fumbling under stress or with gloves. This model includes a Thumb Screw Mount.