The Archangel ERD is a closed emitter pistol red dot in a subcompact sized form factor, with a newly designed optical system delivering a powerful dot with unparalleled efficiency and battery life. The closed emitter housing protects your red dot emitter mechanism from moisture and debris. Compatible with RMSc pistol cuts including Holosun K Series/407k/507k/Modified RMSc. Comes equipped with Shake Awake motion sensing technology. A parallax free 3 MOA red dot reticle with button controlled illumination intensity settings. A side loading battery tray allowing for easy battery replacement without having to unmount your red dot. Rugged 6061 grade aluminum housing sealed for water and fog resistance. Low draw optical system providing up to 50,000 hours of battery life on a single 3V CR1632 lithium ion battery.