Great idea! - MSR TrailShot MicroFilter

This tiny filter works great. It easily fills a water bottle in a minute or you can just drink directly from the top. Water is pumped thru the filter by squeezing the soft side of the container below the mouth piece. The only reason this gets four stars instead of five is because MSR says never allow the filter to freeze because it will destroy the filter fibers. As I am a cold weather camper, this really limits its use for many of my trips.