The HS510C is an open reflex optical sight designed for rifle and carbine applications. Features include Aluminum/Titanium housing; Solar Failsafe allows the red dot sight to remain powered when your battery fails; Holosun’s Super LED with up to 50k hours battery life; 12 brightness setting- 10 daylight & 2 night vision; green 2 MOA Dot/65 MOA circle; parallax free; unlimited eye relief and shake awake. Includes Absolute Co-witness mount, lens cloth, CR2032 battery, T10 L Key and user manual.