SureFire P2X Fury with IntelliBeam Technology Auto-adjusting variable-output LED Intellibeam technology automatically and seamlessly adjusts light output from 15 to 600 lumens depending on Environmental conditions Its high-performance LED and parabolic reflector create a smooth, highly useful beam with a far-reaching center and significant Surround light for maintaining situational awareness First press or click of the tail cap switch selects auto-adjusting intellibeam mode; return to off and press or click on again within one second to Select max-output tactical mode High-strength aerospace aluminum body, Mil-Spec hard anodized for extreme durability; weatherproof--o-ring and gasket Sealed Coated, tempered window resists impact and thermal shock, maximizes light transmission