High brightness, long runtime, waterproofing and reliability are the indispensable characteristics of this headlamp, made to use in an extreme environment. The Fenix HP10 utilizes a Cree XR-E LED (Q5) to throw a high output beam with maximum 225 lumens. The Fenix HP10 is the world's brightest headlamp that runs of AA batteries. A high intensity headlamp, at 225 maximum lumens output, will let you see everything in front of you without occupying your hands. Waterproof to IPX-8 standard that works well even when submerged under water. With its outstanding performance and solid structure, the HP10 is excellent for extreme use like, caving, searching, climbing, outdoor living and more. The HP10 features four different levels of output, allowing you to dim the light as low as 7 lumens - which will run for up to 210 hours! Specifications Cree XR-E LED (Q5) with lifespan of 50,000 hours 4 lighting levels, 3 flashing modes --Lighting mode: 7 lumens (210hrs) -> 50 lumens (22hrs) -> 120 lumens (7.5hrs) -> 225 lumens (Max 2.5hrs) --Flashing mode: Strobe (5 hrs) -> SOS (50 hrs) -> Warning Flash (44 hrs) Max lighting distance: 120 meters Dual switch system with easy operation - one for Lighting on/off, the other for output adjusting. Digitally regulated output - maintains constant brightness Output automatic memory function Overheat protecting system,the lamp goes back to the high output after 3 minutes continuous lighting in Turbo mode. Uses four 1.5V AA ( Alkaline, Ni-MH, Lithium ) batteries, inexpensive and widely available Separated type structure to balance the weight for comfortable wearing Light body:54mm(Length)*43mm(Width)*33.5mm(Height) Battery pack: 84mm(Length)*64mm(Width)*21mm(Height) Lighting head is made of aircraft-grade aluminum, the rest part is made of high quality plastic Premium Type III hard-anodized anti-abrasive finish Light body: 40g, Battery pack: 77g (excluding batteries) Waterproof to IPX-8 Standard (Submarine to 2 meters deep water for 30 minutes continuous lighting) Toughened ultra-clear glass lens with anti-reflective coating