Try a different term, or use the links below to find what you're looking for. If you're really stuck, call a GearHead at 1.800.233.7159.
Out With the Bad
Portable Water Filters Explained
The most important difference between water filters and water purifiers is that water filters do not eliminate viruses. Water filters rely on either gravity or a manual pump to force water through a filter with holes usually about a few tenths of a micron across (1 micron = one-millionth of a meter). While this is small enough to block bacteria and protozoan, many viruses are small enough to pass through. The good news is that viruses are rarely found in North American wilderness waters, so this is mainly only a concern when traveling internationally.
Lightweight and compact, backpacking filters are good options for hiking or traveling. Most are pump-operated and designed to fill your personal water bottle.