aqua mira frontier pro

attaches to your hydration bladder

couple drops of iodine into the bladder in combination with this and away you go

works as a drip filter as well

$25 for unit and $3 for a little bottle of 10% iodine - good to go for less than $30 - cheap cheap

buy one to use and keep a spare in the bug out bag

here is a link to the military model:

http://www.outdoorready.com/aquamira-frontier-pro-filter-military-edition-p-22.html