No pumping, no chemicals, no test strips, no timekeeping, no lubricating, and no replacement filters are required. All that is required is to push the water purifier's button (once for 32 ounces, twice for 16 ounces), place the pen-like lamp in clear water, and stir until an indicator light turns green. Water has no aftertaste after being purified. Measuring 7.6 inches long, the purifier comes with a nylon case and a user's guide. It exceeds U.S. Environmental Protection Agency guidelines for testing microbiological water purifiers

• 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