Holosun HS403B 20mm Micro Red Dot Sight (2 MOA Dot)
The Holosun HS403B is a compact 20mm tube-style red dot built around a 2 MOA dot reticle and digital button controls. It features 12 brightness settings (10 daylight and 2 night-vision compatible) and Holosun Shake Awake technology to extend runtime.
This optic uses a CR2032 battery in a side-mounted tray and is rated IP67 for water resistance. Included with this unit is the installed Picatinny mount and a rubber lens cover.