Holosun HS407K-X2 Reflex Sight Red Dot 6MOAThe 407K X2 is an open reflex sight designed for concealed handgun applications. Features Holosuns Shake Awake technology to activate the LED at the slightest detection of movement and deactivate the LED during periods of motionless. The 407K 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