Water filtration has been the biggest revelation for us on multi-day rides. The ability to re-supply on water in the backcountry is essential. I really love looking at maps for water sources, trying to figure out how much water I need to carry before the next source, pumping the water. We've chosen the MSR Hyperflow filter attached to a MSR 4-liter dromedary bag. I know some folks like steri pens or aqua tabs.  I also bought the Sawyer Mini Filter. But the best feature of the Hyperflow is the flat filter that sits easily in shallow streams, which tend to be our water source. The filter comes with the “Quick Connect bottle adapter” and allows the filter to screw right on to our Dromedary bag. The filter weighs 7.8 oz. and is made nearby in Seattle, WA. More American made product!