The 48321 is a high powered pen light flashlight powered by a single "AAA" battery. The Streamlight’s new high flux LED light with Proprietary Micro Optical Systems has “Battery-Booster” electronics to provide a super-bright beam. Light weight and compact the LED Pen Light will fit nicely in your pocket or pocketbook. The LED light has an output of up to 20 lumens output for brighting up evan the barkest alleyways and corners.  The "AAA" batteries provide up to 1.5 hours of continuous runtime. The Super-bright 1/2 watt, 30,000 hour high flux LED will allow your flashlight to work at that critical moment when you need it. The MicroStream has ann internal polymer body liner and shock proof switch housing allow for operation under the most extreme conditions.