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A compact, lightweight system that lets you drink safely from almost any clear water source without extra fuss.
Hydrapak says:
Lighten your load and drink right from the source. We took our go-to flask and added filtration to create a system that delivers hydration without contamination. The filter — light and compact — screws on top so you can drink right from the flask. Or — if you’re carrying more water — use the system to fill a bottle or reservoir.
*Effectively removes common waterborne bacteria, such as E.coli (99.999%) and parasitic cysts (99.9999%) per HSF 42.
Our Verdict
The Hydrapak Ultraflask+ 500ml Filter Kit integrates a soft flask with a screw-on hollow-fibre filter, offering an efficient, one-piece hydration setup. The flexible TPU flask collapses as you drink, cutting slosh and fitting neatly into a running vest or pack pockets. Flow rate through the bite valve is smooth, and the hollow-fibre element filters bacteria and protozoa effectively with minimal effort.
It’s easy to maintain, too: a small nozzle, included, lets you attach the filter to a clean water bottle and squeeze water through in reverse to clear debris. If you're away for a few days, the nozzle is, unfortunately, one more thing to bring (or, more likely, to lose), but if you're just using the bottle for runes rather than multi-day trips, it works incredibly well.
- Reviewed by Ultralight Outdoor Gear
Features
- A flexible and structured grip makes it easy to hold the flask while screwing and unscrewing the filter.
- Soft material conforms to most hydration packs and larger vest pockets for a secure and stable fit.
- Easy to drink bite valve auto-seals after each sip, eliminating annoying drips.
- 42mm opening lets you fill the flask easily at any water source.
- Flexible design shrinks as you drink, minimizing water movement.
- Plugs into filter valve and threads onto a HydraPak Stow or bottle of clean water for backflushing the filter to restore its flow rate.
- The integrated filter removes Escherichia coli bacteria, Cryptosporidium parvum cysts, and Giardia Lamblia from approximately 1,500 liters of water at a rate of >1L per minute.*
Specifications
- Weight: 66g
- Capacity: 500ml / 17 fl oz
- Dimensions: 240 mm x 70 mm / 9.4 in x 2.8 in
Material & Construction
- TPU, Silicone POM, Hollow Fiber, ABS
- Care: Avoid freezing filter. Freezing may ruin the hollow fiber membrane. If in freezing conditions we recommend you keep the filter in your pocket or near your body to prevent freezing.
