Surefire 6PX-D-BK Pro Dual-output LED Flashlight 600/15 Lumens. The 6PX Pro's high-efficiency LED is virtually immune to failure since there's no filament to burn out or break. Provides two light output levels: pre-focused 600-lumen beam, and a 15-lumen low-output setting that lets you greatly extend the runtime per set of batteries. Press the tailcap switch for momentary-on low, press further to click constant-on low, return to off and press or click on again within two seconds for high. The high-strength aerospace aluminum body is sculpted for a  secure grip and is hard anodized to military specifications for extreme resistance to scratches, abrasion, and corrosion. A polycarbonate micro-textured reflector delivers a comparatively wider beam with generous peripheral light. FEATURES:--Precision micro-textured reflector creates smooth, optimized beam --Tough polycarbonate window resists impact --High-strength aerospace aluminum body --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 --Weatherproof-O-ring and gasket sealed SELECT SPECS: --Output / Runtime -- White Light --High: 600 Lumens / 1.5 hours* --Low: 15 lumens / 52.0 hours* --Length: 5.20 inches --Bezel Diameter: 1.25 inches --Weight w/Batteries: 5.2 ounces --Batteries: 2 x 123A (included) * Runtime per ANSI standard USA