One of the brightest and most compact lights available.  The Fenix E05R2 features include:

•  Uses Cree XP-E LED with a lifespan of 50,000 hours
•  Uses one 1.5 V AAA (Ni-MH, Alkaline) battery
•  2.5" (Length) x .56" (Diameter)
•  less than 1/2 oz weight (excluding battery)
•  Digitally regulated circuit - maintains constant brightness
•  Capable of standing up securely on a flat surface to serve as a candle
•  Reliable twisty switch
•  Made of durable aircraft-grade aluminum
•  Premium Type III hard-anodized anti-abrasive finish

Note: The above-mentioned parameters (tested by 750mAh Ni-MH battery in the lab) are approximate and may vary between flashlights, batteries and environments.