ULTRAFLASK™ SPEED 600ML

Carry more water in a soft flask that is shaped for the front pockets of running vests. The HydraPak UltraFlask™ Speed 600ml combines a generous 600ml capacity with a flexible body that compresses as you drink, helping reduce water movement and empty-bottle bulk.

At just 46g, it is suited to trail running, ultramarathons and fast hiking where every gram matters. The SpeedFill™ cap flips open for rapid aid-station refills, while the wide 42mm mouth makes it easier to add ice or drink mix.

Key features

• Vest-pocket fit: the soft body and wider flange are shaped for larger front pockets on running vests, belts and compact packs.
• Compressible construction: shrinks as the water level drops, reducing sloshing and taking up less space when empty.
• SpeedFill™ cap: flips open for quick refilling and snaps closed for secure transport.
• High-flow bite valve: supports easy drinking on the move and self-seals after each sip to limit drips.
• Large 42mm opening: simplifies filling, cleaning and adding ice or powdered hydration mixes.
• Filter compatible: accepts 42mm threaded backcountry filters, including the HydraPak 42mm Filter Cap.
• Ultralight build: weighs only 46g while providing 600ml of usable capacity.
• Packable design: folds or compresses down when empty for convenient storage after a run.
• Flexible materials: constructed from TPU, PP/POM and silicone.

Specifications

Running-vest fit guidance

The 600ml UltraFlask™ has a wider shape intended for vest pockets approximately 75–100mm wide, 55–60mm deep and 150–200mm long. Pocket shapes vary between packs, so compare these measurements with your vest before purchase.

Recommended use cases

• Trail running and ultramarathons
• Road races and endurance events
• Hydration-vest front pockets
• Fast hiking and lightweight adventures
• Aid-station refills during training or competition
• Backcountry routes when paired with a compatible 42mm filter

Why choose a 600ml soft flask?

The additional capacity can reduce the number of refills needed on longer outings while remaining compact enough for many larger running-vest pockets. Unlike a rigid bottle, the flask conforms to the pocket and becomes smaller as you drink.

Cleaning and care

1. Remove the cap and bite valve components.
2. Wash the flask with mild soap and warm water after use, especially after drink mixes.
3. Use a soft bottle brush through the wide opening when deeper cleaning is needed.
4. Rinse the cap and valve separately to remove residue.
5. Allow every part to dry completely before reassembly and storage.

Compare HydraPak hydration options

Choose the UltraFlask™ Speed 600ml when you want lightweight, easy-to-reach hydration that fits directly into a compatible running-vest pocket.