All survival kits should be stocked with a means to purify water. This MIOX water purifier is the best of the best. It works using mixed oxidants which are then added to untreated water. This treatment kills viruses, bacteria, Giardia, and Cryptosporidium. Because the MIOX Purifier just needs simple camera batteries and salt to operate, and its maintenance-free. It is the ultimate when it comes to water purification technology.