This innovative, automatically adjusting version of the M600 Ultra Scout Light takes full advantage of the variable-output capability of one of SureFire?s brightest and most popular LED WeaponLights. Our proprietary IntelliBeam Technology-an intelligent sensor and microprocessor-based system-continuously evaluates your environment and seamlessly adjusts light output, from 100 up to 600 lumens, based on the scope of your surroundings. Just press or click its tailcap switch to access this auto-adjusting mode, which delivers just the right amount of light output. Return to off and press or click again within one second to activate max-output/tactical mode, which locks in all 600 lumens-ideal when maximum output is what you need. The compact M600IB minimizes added weight, frees up rail space for other accessories, and increases weapon maneuverability compared to larger WeaponLights. It attaches by means of an integral thumbscrew clamp to long guns equipped with a MIL-STD-1913 Picatinny rail. This model comes with an installed click-type pushbutton tailcap switch: press for momentary on, press further to click constant-on. The switch is shrouded to minimize the chance for accidental activation. Constructed of high-strength aerospace aluminum with Mil-Spec Type III hard anodizing for superior toughness and corrosion resistance, the M600IB is O-ring sealed to keep out the elements. And, like all SureFire WeaponLights, it?s built to withstand the rigors of combat..