Holosun HS507K-X2 Reflex Sight Red Dot 2MOA and 32MOA CircleThe 507K X2 is an open reflex sight designed for concealed handgun applications. Features Holosuns Multiple Reticle System giving the user three reticle options. Shake Awake technology activates the LED at the slightest detection of movement and deactivates the LED during periods of motionless. The 507K X2 has 10 daytime brightness levels and 2 night vision compatible levels. 50,000 hours of battery life on setting 6 means you wont be changing