A palm-size hollow-fiber filter that screws onto a soft pouch or a plain water bottle; you squeeze dirty water through it into a bottle or straight into your mouth. People pick it because it is light, fast, cheap to run and works three ways: squeeze, inline on a hydration hose, or as a gravity filter.
Specs
- Filter weight: 3 oz (maker and REI); full kit 8.19 oz (maker)
- Filter: 0.1 micron absolute hollow-fiber membrane (maker)
- Removes: 99.99999% of bacteria and 99.9999% of protozoa; maker also claims 100% of microplastics. Does not treat viruses or chemicals.
- Flow: 1.7 liters per minute (REI)
- Size: filter 2 x 5 in; squeeze pouch 11 x 6 in (REI)
- Includes: two 32 fl oz pouches, inline adapters, gravity tubing, backflush syringe, mesh case (REI)
- Field cleanable by backflushing; fits most disposable water bottle threads
- Warranty: lifetime limited (maker)
- Do not let it freeze; freezing can ruin the membrane
- REI rating: 4.1 of 5 from 579 reviews (as of 2026-10-19)
What reviewers say
OutdoorGearLab calls it a simple, reliable filter for one to three people and likes that it works for drinking at the source, inline on a bladder, or filling bottles. It flows better than Sawyer's smaller Mini and Micro, so you don't have to squeeze as hard, which also means fewer split pouches. The usual complaints are the included pouches, which can wear out and are awkward to fill in still water, and the need to backflush now and then to keep the flow up. It has no virus protection, which is fine for most U.S. and Canadian backcountry water but not for every trip abroad.
Good
- Light and small for a full filter kit
- Good flow for a squeeze filter
- Works as squeeze, inline or gravity filter
- Fits common water bottles
- Lifetime limited warranty
Not so good
- Included pouches can wear out or split
- Needs backflushing to keep flow up
- Ruined if it freezes
- Does not remove viruses or chemicals
Who it's for
Backpackers, paddlers and hunters who drink from creeks and lakes in North America and want a light, proven filter. If you travel where viruses are a concern, or camp in freezing weather and can't keep it warm, look at a purifier or chemical treatment instead.
Sources
Last checked 2026-10-19. Specs from the maker; review notes summarized in our own words.