SterPEN Classic has been proven in the field by Appalachian Trail thru-hikers and Everest climbers. It uses 4 AA batteries that are not included. Batteries are an important choice to make. We strongly recommend Lithium or NiMH (Nickel Metal Hydride) batteries as they deliver 6 to 10 times more doses per set than Alkaline or Nickel Cadmium alternatives. Lithium or NiMH batteries will purify 170-230 16oz. (0.5L) glasses of water. The SteriPEN Classic eliminates viruses, bacteria and protozoa as its Ultraviolet Light (UV) destroys the DNA of microbes. It is effective against Outdoor Microbes like Giardia and Cryptosporidium; Travel Pathogens that cause Diarrhea, Dysentry, Hepatitis, and Legionnaire's Disease; Household Germs such as Bird Flu and Influenzas, E. Coli & Salmonella; and Staph & Strep; Natural Disaster Risks like Botulism, Cholera, Smallpox and Typhoid.
