The HE407C-GR-X2 is an open reflex sight with 2 MOA green dot reticle designed for pistol applications. Features Holosun&';s Shake Awake technology that activates the LED at the slightest detection of movement and deactivates the LED during periods of motionless. The 407C-GR-X2 has 10 daytime brightness levels and 2 night-vision compatible levels. 50,000 hours of battery life on setting 6 means you won&';t be changing batteries often, but when you do need a replacement, the convenient battery tray allows the user to swap batteries without removing the optic from the slide. The 407C-GR-X2 also includes Holosun&';s Solar Failsafe technology to power your optic in the event of battery drain or failure. This optic is parallax-free and has unlimited eye relief. The Holosun 407C-GR-X2 is IP67 waterpoof rated.