Features and Benefits: Reflector optics deliver up to 400% more lighting range than traditional penlights Easily attaches/detaches to just about anything with convenient pocket clip or key ring Up to 96 hours run time Includes neck lanyard O ring sealed for water- resistance The world"s smallest, brightest, one-ounce, machined aluminum, one LED flashlight! The Key-Mate® runs longer and stays brighter, Powered by 4 LR44 high alkaline button cells (included). 100,000 hour lifetime high-intensity LED with reflector optics.