Sawyer’s 0.1 Micron Gravity Filtering System simplifies backcountry hydration needs. This versatile, safe, and highly effective bag system is practically hands free. Just hang the system from a tree or any source off the ground, and gravity does all the work quickly — filtering 2 liters of water in as little as 90 seconds. Packing Sawyer’s Point ONE filter mechanism (rated to 0.1 micron absolute filtration), the Gravity Filtering System removes 99.99999% of all bacteria, such as salmonella, cholera and E.coli, and removes 99.9999% of all protozoa (such as giardia and cryptosporidium). It comes in two sizes (2- and 4-liter) and in two configurations — either a single bag (for filtering into your own container) or a dual-bag package (one for dirty water, one for clean water).