GravityWorks™ 2.0L Water Filters are the easiest way to get clean water in the backcountry. They’re lightweight, require no pumping, and allow you to collect, filter, and transport water anywhere. This video describes the two models and provides tips, tricks and care instructions. All GravityWorks™ filters meet EPA and NSF guidelines for the removal of Bacteria and Protozoa, including Giardia, Cryptosporidium, E. coli, Salmonella and Cholera.