Lightweight, gravity-based microfilter system for backcountry and emergency use * 0.2-micron filter is effective against protozoa, bacteria, and particulate * CleanStream microfilter offers a fast 1.75-liter per minute flow rate * Field cleanable design; 1501 liter cartridge life * Weighs 10.75 ounces; exceeds the EPA guidelines for removal of bacteria and protozoa