My friend has one of these. One summer we decided to go Bear Grylls and took a trip to his uncles out in Oklahoma for about a week. We only brought the cloths on our backs and any food we could fit in a filled camel back plus that water bottle. We wound up running out of food within a day and a half since we couldnt carry much and our water lasted less than that. We found a pond to set up basecamp at, but the water was disgusting. We ran it through this bottle and it came out clean as a whistle. The only problem is that even through it filters out all bacteria and viruses, it doesnt filter out whatever makes water taste the way it does, so it still tastes like water that came out of a cesspool. So for the next couple of days we all drank shit water.