The MSR Guardian Gravity Water Purifier has you covered with safe water around the world, removing viruses, bacteria, protozoa, sediment and microplastics hands-free. Simply hang it while you go about your tasks at the hostel, basecamp or campsite. Originally designed to protect servicemembers in the field, this rugged purifier handles the abuse of travel and meets the NSF P248 military testing standard.FeaturesMeets NSF protocol P248 military testing standard for removing viruses (99.99%), bacteria (99.9999%), protozoa (99.9%), sediment and microplastics from "worst-case" water conditionsTwo-stage purifier includes activated carbon to reduce chemicals and unpleasant tastes and odors10-liter reservoir is easy to fill at sinks and streams alikeNo backflushing requiredUp to 1 liter in 2 minutes with optimal reservoir hang height of 6 feetRugged, military-grade construction