Works on gravity pressure, no pumping required. Ideal for camps, cabins, foreign living, and emergencies. Features same technology as other Katadyn filters, therefore removing all bacteria and parasites through 0.2 micron ceramic element. Filter element(s) to be placed in bucket of raw water with exit tube(s) hanging downward into a bottle or container to collect filtered water. Flow rate of approximately 1.3 gallons per hour. Has a capacity of 5,300 gallons of water.