The Guardian was originally planned for military use and has impressed hikers and campers thoroughly after being brought to the general market. Its self-cleaning structure keeps performance at an impressive level even when using it in waters with sediment. - Made specifically for tough environments: NSF P248 protocol performance for removing virus, bacteria, protozoa and sediment - 0.02 micron filter size, hollow fiber filter - The Guardian uses a part of each stroke for self-cleaning - Withstands freezing and dropping from a height of 1.8 meters - Filtering speed: approx. 2.5 l /minute - Filter life: 10 000+ liters [Käyttöohje](https://d1l67pfsx3wblg.cloudfront.net/pdf/MSR_GuardianPurifier_IN_EN.pdf) *Note!* A water filter or purifier tablets cannot remove the toxins created by algae bloom, and therefore do not make water containing said toxins safe to drink.