The Katadyn Gravity BeFree 3 L filter weighs just 192 grams and purifies up to 2 liters of clean drinking water per minute using gravity. The handling of the water filter is particularly simple: the flexible, BPA- and PVC-free ultralight gravity filter features reliable hollow fiber technology for pure drinking water in the great outdoors. The Hydrapak drinking bag just needs to be filled with water. During the filtration process, the water passes through a 0.1-micron hollow fiber filter, which effectively removes harmful bacteria, cysts, and sediments. The integrated handle makes filling easy, and the carrying strap allows the filter to be transported to the campsite in its filled state and hung on a nearby tree. The outlet hose can be easily removed via a quick-release valve with an automatic shut-off, preventing it from coming into contact with contaminated water during refilling.