Holosun HE403BGR HE403B-GR  MAO Black Anodized 1x 20mm 20mm Tube 2 MOA Green Dot Reticle 2 MOA Dot, HE403B-GR is a 20mm micro sight designed for rifle and carbine applications. HE403B-GR features Holosun's Green Super LED with 50k hour battery life, 10 daylight and 2 night vision compatible reticle intensity settings. Its housing is made from 6061 aluminum and includes both a lower 1/3 co-witness mount (1.63) and a low mount (.75) for low-comb height rifle applications. Additional features include Shake Awake technology, digital buttons for setting changes, rubber lens covers, and a side-mounted battery tray for the 2032 battery. HE403B-GR is a versatile sight for users of all levels.