This purifier's large, liter-sized reservoir gives thirsty adventurers purified water by just squeezing the bottle. - Tainted water within the bottle flows through three purifying stages by squeezing the soft plastic bottle - First-stage filter removes large sediment and disagreeable odors - Second-stage cyst filter traps protozoa in a web of glass fiber - Third-stage ViruStat microbial cartridge kills bacteria and deactivates viruses with iodinated resin - Liter size fits neatly in the pocket of your pack; spout snaps shut for dripless transportation This personal water purification system eliminates the need to carry or locate safe water, whether you are hiking, traveling abroad or contending with a flood or other emergency. Only Exstream places an EPA-registered microbial purification cartridge into a standard sport flask. The result is a personal hydration system that provides complete anti-microbial protection against cysts, bacteria and viruses. It is recommended that the ViruStat Cartridge be changed after 125 refills. Change the Cyst and Pre/Post Filters when water flow becomes constricted. Specifications: - Weight: 8 ounces - Dimensions: 11 x 3 x 3 inches - Material: Glass-fiber/iodinated resin/coconut carbon - Removes/Destroys: Protozoa, bacteria and viruses - Output: 0.3 liters per minute - Field cleanable: No, must change cartridge - Treats 26 gallons per replacement cartridge - Bottle Capacity: 28 oz (after cartridge displacement) Katadyn