The Holosun HE508T-GR is an open reflex optical sight designed for pistol applications. Features include a Titanium housing, Holosun's Super LED with up to 50k hours battery life, Multi-Reticle System, Solar Failsafe, and Shake Awake.Solar Failsafe allows the red dot sight to remain powered when your battery fails. 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.M.R.S. (Multi-Reticle System) gives the user the flexibility to use their optic as they need it. Units with this feature allow the user to turn on or off certain sections of the reticle giving the ability to have the ideal reticle for the job at hand.Holosun Super LEDs provide a versatile range of intensity for the brightest environments down to no-light situations.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).Holosun's use of Grade 5 Titanium in certain Elite Series red dot sights produces unparalleled strength and durability. Holosun Grade 5 Titanium has more than double the tensile strength and as high as five-times the fatigue strength of 7075 Aluminum. Grade 5 Titanium is also able to withstand seawater.Included:T10 L Key User Manual CR1632 Battery Lens Cloth