ThruNite TH10 Cool White 825 Lumen Single CREE XM-L2 U2 LED Headlamp (Cool White) Professional all-day, all-environment and all-metal outdoor LED headlamp Adopts an advanced CREE XM-L2 U2 LED emitter to give out cool white light with the max output up to 825 lumens Powered by a single 18650 battery, two CR123 or two RCR123A batteries (all not included) Can shine as little as 0.2 lumens in it's special Firefly mode - perfect for night-adapted vision or avoiding drawing attention With a built-in SOS signaling mode, which can be essential when roaming out in the wild or confronting a dangerous situation