Simply fill this sport bottle from any fresh water source, squeeze and sip! Water is made safe to drink as it flows through three purifying stages. - First-stage Filter removes large sediment and disagreeable odors - Second-stage Cyst Filter traps protozoa in a web of glass-fiber - Third-stage EPA registered ViruStat Microbial Cartridge disinfects the water from bacteria and viruses with iodinated resin - Fits neatly in a bicycle's water bottle cage or the pocket of your pack; spout snaps shut for dripless transportation - The 26-oz. bottle holds 20-oz. of water after the displacement of filter cartridge This personal hydration system provides complete anti-microbial protection against cysts, bacteria and viruses. It is recommended that the ViruStat Cartridge be changed after 200 refills (26 gallons, depending on water quality). Change the Cyst and Pre/Post Filters when water flow becomes constricted. Specifications: - Weight: 7 ounces - Dimensions: 11 x 3 x 3 inches - Material: Glass fiber/iodine/coconut carbon - Removes/Destroys: Protozoa, bacteria and viruses - Output: 0.3 liters per minute - Field cleanable: No, must change cartridge Katadyn