No pumping required! Just fill and hang the sleek, foldable Katadyn Gravity BeFree 6 L water filter and let gravity do the work. Its EZ-Clean Membrane(TM) filters water at a rate of up to 2 L per minute. Features Water passes through the EZ-Clean Membrane hollow-fiber filter, which removes bacteria, cysts and sediment with its pore size of 0.1 microns Filters water at an impressive rate of up to 2 liters per minute Included carry strap makes it easy to hang the durable and collapsible 6-liter reservoir Water-level indicator window makes it easy to see how much water remains in the reservoir bag Filtered water can be stored in separate bottle or reservoir (not included) Simply shake or swish the EZ-Clean Membrane to remove debris Tested up to 1,000 liters; individual results will depend on water quality Quick-connect hose allows easy on/off for filling and storage Includes hanging straps and zippered storage bag