The Frontier Emergency Water Filter System is ideal for hiking, travel, and emergency preparedness. It is the perfect addition to your 72 hour emergency kit. One unit will filter up to 30 gallons (110L) of water. The Frontier Filter is tested and certified to remove 99.9% of Cryptosporidium and Giardia. The Frontier Emergency Water Filter System is also easy to operate, just attach and expand the straw, submerge the filter end into the water source, and drink through the straw.