MSR WaterWorks EX Water Filter Pump:
Pumping water ranks down there with washing dishes on the favorite chore lists of most backcountry enthusiasts. While we can't do anything about the discomfort of stooping over a stream or lake, the WaterWorks EX reduces your time spent on task, especially if you're supplying water to a large group or a well-equipped base camp. The WaterWorks EX features a practical device called an AirSpring Accumulator to improve your water pumping efficiency about a liter per minute--a 45% improvement compared to similarly sized filters. It works by trapping an air bubble inside the redesigned filter housing. This air bubble compresses on the down stroke to store energy then expands on the upstroke to push water further through the ceramic cartridge. Because the inside of the cartridge is under constant pressure, more water flows through in less time. That adds up to more break time during your breaks--which is a good thing at any altitude.