Filtering up to 1.75 liters a minute without any pumping, the high-capacity GravityWorks Water Filter System filter is one of the easiest and fastest ways to get filtered water in the backcountry. Ideal for bigger backpacking! Either model easily supplies filtered water for drinking, washing up, cooking, and cleaning. Simplify your water collection with the GravityWorks system and spend more time enjoying your group. No pumping: Just fill the dirty reservoir, hang it, and let gravity do the hard work-yep, filtering water can be as easy as fill, hang, relax Effective: Every microfilter is individually tested to ensure it meets all EPA & NSF guidelines for the removal of 99.9999% of bacteria and 99.9% of protozoa* Easy collecting & dispensing: Collecting water is easy-simply open the top, scoop water, and close; control delivery of filtered water with hose shutoff clamp Cartridge life: 1500 Liters Field cleanable