"Just got back from Thailand and am so glad we had the Aquamira filter straw with us. Many of our tour group were getting sick but my family stayed healthy. We received bottled water everywhere but it was local water, so the straw was needed. Even our tour guide wanted one because he also travels to some remote areas and thought it would be good to have along just in case. It was the best investment for our trip."An excellent emergency back-up filter when packing into remote country, or even when traveling abroad, the Frontier Water Filter Straw safely filters contaminants down to two microns in size, including commonly found pathogens such as giardia and cryptosporidium. Can be used to drink from any bottle, cup or directly from water sources. Ultra-lightweight and compact size fits easily into the smallest daypack, fanny pack, or emergency kit. One unit will filter up to 20 gallons (75L) of water. Tests indicate that the Frontier Filter will 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. Weighs less than one ounce.