The HE503CU-GR is a 20mm micro sight designed for rifle and carbine applications. HE503CU-GR features Holosuns Solar Failsafe technology and our Multi-Reticle System (MRS) which includes a 2MOA dot and a 65 MOA Circle. Holosuns Green Super LED allows for up to 50k hour battery life with 10 daylight and 2 night vision compatible reticle intensity settings.The HE503CU-GR 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, rubber lens covers, and a side battery for the 2032 battery. HE503CU-GR is a versatile sight for users of all levels.