The HS503CU is an open reflex optical sight designed rifle and carbine applications.Features include Aluminum housing, Holosun's Super LED with up to 50k hours battery life; 12 brightness setting- 10 Daylight & 2 night vision; 2 MOA Dot/65 MOA circle; parallax free and unlimited eye relief; solar failsafe and shake awake. Includes Lower 1/3 Cowitness mount, low profile mount, rubber cover, lens cloth, CR1632 battery, T10 L Key and user manual.