The Fenix E11 LED Waterproof Flashlight is a portable and durable flashlight made of aircraft grade aluminum. It requires only a single AA battery (included) that provides around eight hours of uninterrupted light on the low setting, and the LED bulb gives off a constant brightness of 115 lumens with a total lifespan of 50,000 hours of usage. Included with the light is a lanyard, spare O-ring, and spare rubber switch boot.