Frontierô Emergency Water Filter System The ideal "just in case" filter for emergency use when traveling, hiking and fishing. Also ideal as a backup filter for multi-day backpacking trips. The Frontier Filter can be used to drink from any bottle or cup, or directly from water sources. Removes contaminates down to 2 microns in size including wide spread pathogens such as giardia, cryptosporidium and large bacteria. Frontier's ultra lightweight and compact package size fits in the smallest day pack, waist pack or pocket.