Drinking straight from crystalline mountain streams is nice in principle, but a lot less awesome when you end up running for the bushes every five minutes for the rest of the commute. There are many how you can help save yourself from waterborne bummers, but none that are as effective, easy to use, and reliable as the MSR Guardian Purifier System. Developed for, and along side, the US military, the Guardian uses new Hollow Fiber technology to filter out just about everything (protozoa, bacteria, particulate, and even viruses), so you’ll sip fresh, clean water without first checking that you packed extra TP. The Guardian has an easy pump-action design that can filter up to 2. 5 liters per minute, and an ingenious self-cleaning design–10% of the water from every stroke flushes contaminants from the filter, so it never gets clogged or becomes less effective. The wastewater is discharged through a tube that runs parallel to the intake, so it empties easily back into the water source. MSR also included a water-bottle adapter for easy fill-ups, and a cartridge life indicator that permits you to know when it is time to switch (even though the included filter is good for no less than 10,000L, so it might be a even as before it’s that time).
Purifying Element: Hollow Fiber
Eliminates: protozoa, bacteria, viruses, particulate
Pore Size: 0.02 micron
Cartridge Life: 10,000+ L