The Platypus Gravityworks Filter combines the efficiency of pump-free water treatment with lightweight and compact storage. . Two reservoirs clearly marked, CLEAN and DIRTY to prevent mix-ups. Ultra-fast filters 4 liters (140 oz.) of water in 2.5 minutes. Exceeds EPA guidelines for removal of bacteria and protozoa. Streamlined filter housing and zipperless Clean reservoir save weight. Reinforced handles for hanging and carrying. SlimeGuard antimicrobial treatment for lasting, taste-free performance. Easy to clean; back flushes in seconds 40818070147 26926700015 3135