Run fast and filter faster with the UltraFlask Filter Cap, designed to seamlessly thread onto HydraPak’s 42 mm running flasks and handhelds. Offering a lightweight and easy filtration solution, it features a traditional bite valve and cap design, allowing runners to drink freshly filtered water directly through the high-flow Blaster valve.

Perfect for trail runners and endurance athletes, the UltraFlask Filter Cap combines lightweight convenience with effective water filtration, so you can stay hydrated without slowing down.

• Fast and Safe FiltrationRemoves Escherichia coli bacteria, Cryptosporidium parvum cysts, and Giardia Lamblia from up to 1,500 litres of water at a rate of >1L per minute.*
• Light and CompactMinimalist design and lightweight materials make it an ideal filtration choice for runners, adding no extra bulk whether stored or threaded directly onto a flask.
• High-Flow DesignThe Blaster bite valve auto-seals after every sip, ensuring a smooth drinking experience without leaks or drips.
• 42 mm Thread CompatibilityFits easily onto HydraPak's running soft flasks, flexible bottles, and other water storage containers with a 42 mm thread.
• Included Backflush AdapterRestore flow rate by backflushing the filter using a HydraPak Stow or a clean water bottle, ensuring long-lasting performance.
• *Effectively removes common waterborne bacteria, such as E.coli (99.999%) and parasitic cysts (99.9999%) per HSF 42.