Destroys viruses, bacteria and protozoa--including Giardia and Cryptosporidium--using ultraviolet (UV) light * Takes 48 seconds to purify 16 ounces of fluid, 90 seconds for 32 ounces * Easy to use--just press a button to start and the SteriPEN shuts off when purification is complete * No pumping, no chemicals, no test strips, no timekeeping, no lubricating, and no replacement filters required * Powered by 4 AA batteries; weighs 8 ounces and measures 7.6 inches long