The HE407C-GR-X2 is an open reflex sight with 2 MOA green dot reticle designed for pistol applications. Features Holosuns 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 wont 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 Holosuns 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.