Don't let the name "Junior" fool you. The Streamlight Jr. LED lights may be lightweight and compact, but the light they produce is anything but small. C4 LED technology emits a blast of bright light with a far-reaching beam that you'd never expect from a flashlight this size. And the Jr. LED series of lights are big on dependability too. They run up to 4 continuous hours on two "AA" alkaline batteries.- Powered by two "AA" alkaline batteries (included) or two "AA" lithium batteries.- 1 watt C4 LED, 50,000-hr. LED- Up to 3800 candela (peak beam intensity) and 85 lumens measured system output- Runtime to the 10% output level:- "AA" Alkaline Batteries 4 Hours- "AA" (L91) Lithium Batteries 5.25 Hours- Push button tail switch - momentary or constant on operation- Shock-resistant / water-resistant- Includes black nylon flapless holster- 6.5" long- 4.1 oz.