Cree XP-E LED (R2) with lifespan of 50,000 hours Three levels of output: 32 Lumens (5hrs) -> 4 Lumens (23hrs) -> 100 Lumens (1.5hrs) Uses two 1.5V AAA (Ni-MH, Alkaline) batteries, inexpensive and widely available Working voltage:1.8-3.2V 149.5mm (Length) x 14mm (Diameter) Made of durable stainless steel and aluminum Premium Type III hard-anodized anti-abrasive finish 44.5-gram weight (excluding batteries) Waterproof to IPX-8 Standard Toughened ultra-clear glass lens with anti-reflective coating Push-button tail cap switch Included accessories: two spare o-rings