A 1-liter soft flask with a filter built into the cap: dip it in a stream, screw on the cap and drink or squeeze. People pick it for fast flow, a wide mouth that fills easily and how flat it packs.
Specs
- Weight: 76 g (maker); REI lists 2.7 oz
- Capacity: 1 liter flask
- Size: 10.75 x 4.2 x 3 in (REI)
- Flow: up to 2 liters per minute (maker and REI)
- Filter: hollow-fiber EZ-Clean membrane plus optional activated carbon pad
- Removes: bacteria, protozoa, cysts, sediment and microplastics; carbon pad improves taste, such as chlorine from tap water (maker). Not for viruses.
- Filter life: hollow fiber up to 1,000 liters; carbon pad up to 200 liters, depending on water quality (maker)
- Flask: TPU, BPA free (REI)
- Cleaning: shake or swish in water; no backflush tools
- REI rating: 4.7 of 5 from 132 reviews (as of 2026-10-19)
What reviewers say
Reviewers like how simple it is: fill, cap, squeeze, drink. The flow is fast with little effort, and the wide mouth fills well from shallow creeks. Better Trail says the new double-layer flask fixes the pinhole leaks and loose cap parts that hurt older BeFree versions, though they did not notice much difference from the carbon pad. A Hiking Daily tester used it for a year on Colorado hikes with no leaks or clogs, but rated it lower for silty or muddy water. Cleaning by shaking is easy but less thorough than a backflush, so flow can drop over time in dirty water.
Good
- Fast flow with light squeezing
- Wide mouth fills easily
- Packs flat when empty
- Tougher flask than older BeFree models
- Easy cleaning, no tools
Not so good
- Small batch size; not great for filtering for a group
- Slows down in silty or muddy water
- Shake-cleaning is less thorough than backflushing
- No virus protection
Who it's for
Day hikers, trail runners and paddlers who refill often from clear water and want to carry less weight. Groups and anyone filtering murky water at camp will do better with a gravity filter or the Sawyer Squeeze.
Sources
Last checked 2026-10-19. Specs from the maker; review notes summarized in our own words.