ThruNite TH10 Headlamp Flashlight 825 Lumen Single CREE XM-L2 U2 LED (TH10 XM-L2 CW + U1 +34001) Featuring the advanced CREE XM-L2 LED emitter, with a lifespan of over 20 years, the TH10 is able to put out 825 lumens using just a single 18650 battery. For great versatility, it can also accept two CR123 or two RCR123A batteries. The TH10 is also able to shine as little as 0.2 lumens in its special Firefly modeperfect for night-adapted vision or avoiding drawing attention. The entire body of this headlamp is made from aircraft grade aluminum, which gives it exceptional durability and excellent heat dissipation, allowing it to maintain high output for extended periods of time. The TH10 includes a built-in SOS signaling mode, which can be essential when roaming out in the wild or confronting a dangerous situation. The TH10 also features instant access to Turbo mode, the maximum output, from any mode. This means no matter what mode youre using, or even if the light is off, you always have the max brightness available right when you need it most.