Their first hand-held, lithium battery-powered programmable flashlight that provides 600 lumens of light with 253 meters of beam distance. Ten-Tap Programming Choice of three user selectable programs: 1.) high/strobe/low 2.) high only 3.) low/high. C4 LED technology, impervious to shock with a 50,000 hour lifetime. 3 light output levels: High 16,000 candela peak beam intensity, 600 Lumens, 1.25 hours runtime, Low 800 candela peak beam intensity, 33 Lumens, 18 hours runtime. Strobe - 2.5 hours runtime, Multi-function, push-button tail switch for one-handed operation. Optimized electronics provide regulated intensity. Durable anodized machined aircraft aluminum construction. Anti-roll head prevents the light from rolling away when you set it down. Removable pocket clip. O-ring sealed glass lens. IPX7; waterproof to 1 meter for 30 minutes. 1 meter impact resistance tested. Uses two 3V CR123A lithium batteries (included).