Virtually indestructible LED emitter regulated to maximize light output and runtime; Two output levels: high for maximum light, low for extended runtime; Precision micro-textured reflector creates smooth, optimized beam; Tough polycarbonate window resists impact; High-strength aerospace aluminum body; Mil-Spec hard-anodized for extreme durability; Dual-output tailcap click switch: press for momentary-on low, click for constant-on low, return to off then press or click again for high; O-ring and gasket sealed for waterproof, weatherproof reliability; Includes high-energy 123A batteries