This is a EOTech Night Vision Sight known as the Holographic Hybrid Sights, model HHS I.
The Holographic Hybrid Sight I (HHS I) features an EXPS3-4 with a G33.STS magnifier. 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.
Features:
30 total brightness settings
10 are night vision settings
Fog resistant internal optics
Fits MIL-STD-1913 rail 1 Weaver