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.  With two sizes- 4L and 6L-GravityWorks is ideal for bigger backpacking groups or basecamps. Offering an 8 liter or 12 liter total capacity, this 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.