I ran into Doug with Survival Solutions at a Boise Sportsmen's show and he had the neatest little gizmo. Let me set the scene. You're on a long hike or deep into the wilderness on a hunt or way out in the middle of the lake on a hot, sunny day and all of a sudden you realize you're dying of thirst. What to do? "You have a survival bottle and I can go into the wilderness, take it away. It is a 2 µ absolute filter that will take out anything that can hurt you, Giardia, Cryptosporidium, E. coli, toxic chemicals, dissolved solids, anything. So I'm out on a mule deer hunt and all of a sudden I'm dying of thirst and I find a mud pond. Can we use your filter? You bet. Just scoop it up, screw the lid on and suck. It comes out crystal clear, no odor, no taste and we take out anything that can hurt you. How much? $25 for one or $40 for two. It is made by Seychelle and it is all made in the United States. One bottle will do about 150 gallons, any water, anywhere. It will plug up slowly and for $15 you can replace the filter and do it all over again.