This is a EOTech Night Vision Sight known as the 558, model 558.A65.
Perfect for anyone that doesn't like to sacrifice. The 558 is compatible with Gen-I-III night vision devices and features an adjustable" locking quick detach mount that offers instant removal. The operational buttons are located on the side of the sight making this optic ideal for use with EOTech switch-to-side magnifiers. The drop-in replacement Laser Battery Caps (LBC and LBC2) are designed to work with this model as well" increasing your aiming capabilities and speed to target all day and night long.
Features:
Water Resistant
Fits weaver or MIL-STD-1913 rail
20 daylight settings
10 settings for Gen 1-3+ night vision