With military-grade engineering and game-changing technology, the Guardian Purifier is simply the safest, easiest way to purify water virtually anywhere on earth. No more chemicals, prefiltering, bulbs, batteries or waiting 2.5L per minute Treats up to 10,000+ L Withstands freezing & drop testing Revolutionary Self-Cleaning Performance On every stroke, the purifier uses 10% of its water to flush the contaminants in its filter back into the source. Physically removes: Viruses, bacteria, protozoa and particulate.