On longer outdoor adventures where the drinking water supply becomes an issue, you need a purifier. MSR’s Guardian system is it. This medical-grade system offers top-of-the-line technology that quickly & easily eliminates all bacteria, viruses and protozoa. Yes, all. No need for a UV filter backup. The Guardian is also fast: it purifies 2.5 liters of water in just 60 seconds. Available January 2016.