The revolutionary SureFire M600IB is a sophisticated, innovative member of SureFire's Scout Light Family. It utilizes a proprietary IntelliBeam Technology, an intelligent sensor and microprocessor-based system that continuously evaluates the environment where the beam is aimed, to automatically adjust the light output to the optimal level, between 100 and 600 lumens, faster than the human eye can detect. Its high-performance LED and parabolic reflector creates a smooth, highly useful beam with far-reaching center and significant surround light for maintaining situational awareness no matter to which output level the M600IB's beam is automatically set. It is constructed of Mil-Spec hard anodized aluminum and O-ring and gasket sealed. The M600IB attaches quickly and securely via its thumbscrew mount to any MIL-STD 1913 rail.