Holosun HS407 V2 Red Dot Sight | Energizer Coin Battery CR1632 | Picatinny Mount | T10 L Key | Lens Cloth | User ManualLONG BATTERY LIFE: Features include Holosun’s Super LED with up to 50k hours battery lifeADVANCED TECHNOLOGY: There are 12 different brightness settings, including dim settings compatible with night-vision devices for nighttime use. Parallax free optical design, with unlimited eye reliefSHAKE AWAKE: Holosun’s Shake Awake Technology shuts the LED off during periods of motionlessness. The amount of time it takes for the LED to deactivate (enter Sleep Mode) is user programmable. Shake Awake can also be completely deactivated which keeps the optic powered on for up to 100k hours (certain models)..SOLAR FAILSAFE: Holosun optics with Solar Failsafe feature automatic brightness adjustment; when you’re under the sun you have a bright reticle, when you move indoors it will automatically dim down to match ambient lighting conditions. Solar Failsafe allows the red dot sight to remain powered when your battery fails.