In conjunction with Mountain Safety Research (MSR), the market leader in water purification, CamelBak’s improved HydroLink™ In-Line MicroFilter is 20% smaller, 50% lighter and boasts a usable filtering life of 300 L (twice that of its predecessor). Designed for use with CamelBak® reservoirs* and Source Hydration Bladders, it allows users to collect water from any source and filter it as they drink. *HydroLink Adapters may be needed on some older units without quick connectors. See picture. An inline water filter, combat tested and in use by the United States Marine Corps. MSR Cascade Designs has this to say about The InLine Filter: "Part of the IWPS (Individual Water Purification System), The InLine MicroFilter allows the users to quickly collect unfiltered drinking water into the reservoir and filter it as they drink. The hollow fiber module instantly removes bacteria, protozoa, protozoal cysts, and sediment, while the activated carbon helps to remove taste and odor in the water". "The InLine Filter does not remove viruses". Water treatment with a product like Chlor-Floc or Iodine** Water Treatment tablets will be needed to treat for viruses. Instruction sheet included. Brand new in sealed package. genuine U.S. Marine Corps issue item. Fits many CamelBak and other hydration units.