doug wrote an answer about Katadyn MyBottle Purifier Bottle on October 17, 2011
ive been using this system for years in Pisgah and the AT. i have not ever had an issue getting any GI bugs. i just dip it into the stream and BAM... fresh water. this system also has the advantage of getting fresh water from slow dripping questionable sources where a pump would be useless. water on the threads is fine, just keep the mouthpiece clean.