The Holographic Hybrid Sight I (HHS I) features anEXPS3-4with aG33.STSmagnifier. It has great utility for any shooter, whose target ranges vary from close to mid-range. The HHS I provides a solution for engaging threats in close-quarter combat situations, then quickly transitions to a 600-meter targeting or surveillance situation. A quick switch-to-side (STS) mount offers simple, fast disengagement of the G33 magnifier. The durable, night-vision-compatible system offers wide-field optical performance with superior light transmission for visibility in extreme low-light conditions. Water Resistant: Submersible to 33 ft (10 m) depth; Mount: MIL-STD-1913 rail 1" Weaver; Brightness: 30 total brightness settings; 10 are night vision settings; Power Source: One 123 lithium battery; Battery Life: Approx. 600 continuous hours at nominal setting 12 at room temp. Fixed Magnification: 3X.