Katadyn · BeFree AC · 1 litre · slate blue
Katadyn BeFree AC 1.0L Slate Blue
one litre, 76 grams, two filter stages
A litre of range between water sources, and when empty the flask rolls up to the size of your palm. The activated carbon stage takes the aftertaste out of the water as well.
Buy the Katadyn BeFree AC 1.0L Slate Blue – one litre in the standard version
The Katadyn BeFree AC 1.0L in slate blue is a drinking flask with an integrated water filter for trekking, mountain tours and travel. The single-wall Hydrapak soft flask holds one litre, weighs 76 grams empty and rolls up when not in use. Filtration is two-stage: the EZ-Clean Membrane with its 0.1 µm pore size retains bacteria, protozoa, sediment and microplastics, while the activated carbon core behind it reduces chlorine along with taste and odour compounds. You drink straight from the flask – no pump, no waiting.
One thread for the whole range
Why the system size makes the difference when you reorder
All BeFree AC models – the 0.5-litre soft flask, this 1.0-litre version and the rigid 0.7-litre bottle – use the same 42 mm thread. That sounds like a technical detail but decides how easily the system stays alive over years: the filter cartridge, the activated carbon refill packs, the flip cap and the silicone mouthpieces fit right across the range. If you own two BeFree AC flasks in different sizes, you only need to stock the spares once. And if a flask is eventually damaged, the still-good cartridge simply moves into the next one. The one exception: the Gravity models use a different filter design and are therefore not compatible.
Single-wall or double-layer – the two 1.0-litre variants
The BeFree AC 1.0L comes in two versions that differ in more than colour. This slate blue one uses the single-wall soft flask – the classic, light construction that rolls up smallest when empty. The black variant is built in a double layer: a second material layer gives more structure and abrasion resistance for harsh conditions. Filter technology, volume, dimensions and thread are identical on both. For normal trekking and travel use the single-wall version is enough; if you regularly carry the flask unprotected among stove, crampons and tent pegs, the double-layer one serves you better.
The carbon stage – and why it unscrews
The two filter stages last different lengths of time: the EZ-Clean Membrane is rated for up to 1'000 litres, the activated carbon core for around 200. That is intentional, because the carbon stage unscrews from the cap. Once exhausted, you remove it and carry on filtering with the membrane – or fit a new one from the activated carbon refill pack. The same move helps when you need speed: without the second stage the flow rises noticeably. At clear mountain streams people therefore often leave the carbon off and fit it only where chlorine or algal notes are a nuisance.
What the filter does – and what it does not
The 0.1 µm membrane retains bacteria, protozoa, sediment and microplastics; the activated carbon reduces chlorine along with taste and odour compounds. Viruses are smaller than 0.1 µm and pass through – in regions with that risk you need additional chemical disinfection or UV treatment. Heavy metals and salt are not removed; the carbon content of a drinking flask is too small for that.
Key features – Katadyn BeFree AC 1.0L Slate Blue
- 🥤 1 litre Hydrapak soft flask · colour slate blue
- 🧵 Single-wall construction – light and rolls up when empty
- ⚖️ 76 g when empty
- 🔀 Two-stage filtration – EZ-Clean Membrane plus activated carbon
- 🔬 Pore size 0.1 µm · hollow fibre
- 💧 Membrane up to 1'000 L · carbon up to 200 L
- 🔓 Carbon stage unscrews – can also be run without it
- ⏱️ Up to 2 L/min (membrane, without the carbon stage)
- 🦠 Removes bacteria, protozoa, sediment, microplastics
- ⚫ Reduces chlorine, taste and odour compounds
- 🔩 42 mm thread – compatible with the BeFree AC accessories
- 🧼 Cleaned by shaking – no tools required
- 🚫 Not effective against viruses, heavy metals and salt
- 🇨🇭 Katadyn · Swiss water treatment since 1928
Slate blue or black – and what you reorder later
The two 1.0-litre variants differ in flask construction: slate blue is single-wall and therefore the lighter version that rolls up more compactly, black is double-layer and more resistant to abrasion. Filtration, volume and thread are identical. More important than the choice between them is what comes afterwards: because all BeFree AC models use the same 42 mm thread, the filter cartridge, activated carbon refill pack, flip cap and silicone mouthpiece fit across the range. One set of spares therefore also covers a second flask. Buy the Katadyn BeFree AC 1.0L Slate Blue at Swiss-Sale.ch – your Swiss specialist shop for outdoor gear with fast shipping.
Who is the Katadyn BeFree AC 1.0L Slate Blue for?
The 1.0-litre filter flask is aimed at trekkers, mountain walkers and travellers who bridge longer stretches between water sources and want a flask that takes up almost no space when empty.
Technical Specifications – Katadyn BeFree AC 1.0L Slate Blue
| Model | Katadyn BeFree AC 1.0L |
|---|---|
| Brand | Katadyn |
| Product type | Water filter (filter flask) |
| Colour | Slate blue |
| Filtration | |
| Design | Two-stage – EZ-Clean Membrane and activated carbon core |
| Filter technology | EZ-Clean Membrane™ · hollow fibre |
| Pore size | 0.1 µm (0.0001 mm) |
| Flow rate | up to 2 L/min (membrane) |
| Membrane capacity | up to 1'000 L (depending on water quality) |
| Carbon capacity | up to 200 L |
| Removes | Bacteria · protozoa · sediment · microplastics |
| Reduces | Chlorine · taste and odour compounds |
| Does not remove | Viruses · heavy metals · salt |
| Cleaning | Shake the filter in water – no tools |
| Flask | |
| Volume | 1.0 L |
| Construction | Single-wall soft flask – rolls up when empty |
| Flask material | TPU · PVC- and BPA-free |
| Thread | 42 mm |
| Compatibility | BeFree AC filter cartridge, carbon refill pack, flip cap, silicone mouthpiece |
| Not compatible | BeFree Gravity models |
| Dimensions & identification | |
| Weight | 76 g |
| Dimensions | 27.3 × 10.7 × 7.8 cm |
| Manufacturer part no. | 8021402 |
| EAN | 0604375214026 |
| Warranty | 2 years manufacturer warranty + 2 years Swiss statutory warranty |
Package Contents – Katadyn BeFree AC 1.0L Slate Blue
- 🥤 Katadyn BeFree AC 1.0L soft flask, slate blue
- 🔬 BeFree filter EZ-Clean Membrane
- ⚫ Activated carbon stage removable
Frequently Asked Questions – Katadyn BeFree AC 1.0L Slate Blue
Answers around the Katadyn BeFree AC 1.0L Slate Blue – from flask construction and the 42 mm thread to the carbon stage and Swiss shipping.
