Product Description
You're three miles into a long run and your flask is flopping around in your vest pocket like it has a mind of its own. Or worse—it's so snug you can barely get it back in after taking a sip. The problem isn't your vest. It's that most flasks are designed for one specific brand, leaving you stuck with compatibility issues.
The Hydrapak Ultraflask Speed is the Swiss Army knife of soft flasks—engineered to fit virtually any running vest or pack on the market. This is the flask that actually works with what you already own.
An Ultra-Fast Ultraflask
Wider Body, Better Stability – The 500ml Ultraflask Speed uses a wider profile than tall, narrow competitor flasks. That means it sits securely in your vest pockets without sinking down or bouncing around as you drink. The result? Less movement, better balance, and no more digging around mid-stride to find your water.
When Speed Is The Need – The SpeedFill is a flip-top cap opens with one hand and snaps shut leak-proof. At aid stations, you're in and out in seconds—no fumbling with screw caps while you're trying to maintain pace. The 42mm opening is wide enough for ice cubes and drink mix powder without the usual wrestling match.
Collapses as You Drink – Made from ultra-durable TPU material, this flask shrinks down as you hydrate. That eliminates the sloshing sound and feel that drives runners crazy with rigid bottles. Empty? It packs down to almost nothing in your pocket or pack.
The high-flow bite valve delivers water when you want it and auto-seals after each sip—no drips, no mess, no sticky jersey. The RF-welded seams handle everything from frozen pre-dawn starts to scorching midday heat without leaking or splitting. Plus, it's compatible with 42mm threaded water filters, making it trail-run ready when you need to refill from streams.
Used by ultrarunners at UTMB and weekend warriors crushing local 10Ks alike. The Ultraflask Speed hits that sweet spot between premium performance and everyday reliability at just 42 grams—lighter than most gels you're carrying.
For gear that arrives damaged or falls under the manufacturer's warranty: Please send a photo of the damage or error message to hello@thefeed.com. We will either help process a claim for the product and a replacement product or store credit will be provided, or we will direct you towards the correct place to make a warranty claim for the product. For returns on gear that you have used, we follow the manufacturer's instructions for satisfaction guarantees. This is specific to each gear product, terms and conditions may change.
Hydrapak Ultraflask Speed FAQ's
Everything you need to know before getting started.
Hand wash with warm soapy water after each use, paying special attention to the bite valve and cap threads. You can use a bottle brush for the interior. Let it air dry completely before storing. Do not put in the dishwasher or microwave.
The Ultraflask Speed is designed with a wider, shorter profile to fit the widest range of vest brands including Salomon, Nathan, Ultimate Direction, and more. It fits most vest front pockets and pack side pockets. The soft, flexible TPU material conforms to your pocket shape for a secure, stable fit.
No. The Ultraflask Speed has a maximum temperature rating of 60°C (140°F). It's designed for cold to room temperature liquids. For hot beverages, use an insulated bottle designed for that purpose.
No, the Ultraflask Speed is designed as a vest/pack flask, not a handheld. If you need a handheld option, check out the Hydrapak SkyFlask Speed IT which includes an integrated hand strap.
Yes! The Ultraflask Speed can be frozen (down to -20°C) with water or electrolyte mix inside. Many runners pre-freeze their flasks for hot weather runs. Just don't fill it completely full to allow for expansion.