The SteriPEN Emergency water purifier is strong, sturdy and reliable. You can consistently rely on the Emergency to provide you with access to safe drinking water in a time of crisis. Affordable and efficient, the Emergency purifies 200 half-liter servings of water on just one set of AA lithium batteries, enough to see your family comfortably through any problem time. The Emergency is designed to fit perfectly into commercial water bottles, forming a seal that lets you keep the water in the original bottle for purification. Just insert the Emergency securely into the mouth of the bottle, turn it upside down, and you have safe drinking water in less than a minute. The process is simple but effective, destroying over 99.9 percent of harmful microorganisms including viruses, bacteria , protozoa, Giardia and Cryptosporidium. In addition to being safe and effective, UV light does not alter the taste, pH, or other properties of the water, and works without the introduction of chemicals to the water. SteriPEN recommends Lithium or Nickel Metal Hydride batteries. Alkaline batteries of any kind are not recommended.Purifies 16oz. In 48 seconds; 32 oz. in 90 seconds.Destroys bacteria, viruses and protozoa that could make you sick in seconds.Fast, compact and easy to use.Durable quartz sheath.Water sensor shut off.Integrated microprocessor.Tapered end for water bottles.Durable construction in bright emergency red.Size: 7.6 x1.5Weight: 5.7 oz.UV lamp life: 3,000 treatments.Battery life: 200 treatments 16 oz. (0.5L) water.Battery: 4 AA Lithium batteries (not included).