Brand: HydraPak
Category: Running Water Bottles & Flasks
Recommended by SoCalTrail Events, SoCalTrail — Southern California
The UltraFlask™ Speed 500ml is a versatile and lightweight hydration solution designed for active individuals. Its innovative design ensures a secure fit in your gear while providing quick access to hydration during your most demanding activities. 1. Made from lightweight TPU material, ensuring durability without adding bulk. 2. Features a wider form for enhanced stability and easy handling during use. 3. Equipped with a 3D welded bottom for added durability and a secure base. 4. Includes the SpeedFill™ Cap, allowing for rapid refills on-the-go. 5. Compact design that easily fits into most running packs and vest pockets. 6. Soft and pliable construction enables it to pack down for convenient storage. 7. Holds up to 500ml (17oz) of liquid, perfect for extended outdoor activities. The UltraFlask™ Speed 500ml is ideal for trail runners, hikers, and outdoor enthusiasts seeking a reliable hydration solution. It performs best in active environments, such as during races or long-distance training sessions. Designed for users of all skill levels, this flask excels in scenarios where quick access to water is essential, making it a must-have for summer adventures or high-intensity workouts.
Price: $17.6 - $22
- Who it's for
- Trail runners and ultramarathon racers who carry water in vest pockets, especially those doing long efforts like 100-milers. Also suits backcountry users who pair soft flasks with a filter cap for lightweight water management.
- What people are saying
- Hosts consistently praise the minimal slosh, easy refilling, and vest-pocket fit; the snap/Speedfill cap gets specific credit for on-the-go drinking. One host recommends sizing up to the 600ml for longer mountain runs, suggesting 500ml can feel limiting.
- Worth noting
- The Speedfill cap can come undone when stored inside a pack without the filter top — worth monitoring. Works with filter caps for backcountry use.
Frequently asked questions
Who is the UltraFlask™ Speed 500ml for?
Trail runners and ultramarathon racers who carry water in vest pockets, especially those doing long efforts like 100-milers. Also suits backcountry users who pair soft flasks with a filter cap for lightweight water management.
What do experts say about the UltraFlask™ Speed 500ml?
Hosts consistently praise the minimal slosh, easy refilling, and vest-pocket fit; the snap/Speedfill cap gets specific credit for on-the-go drinking. One host recommends sizing up to the 600ml for longer mountain runs, suggesting 500ml can feel limiting.
What should you know before buying the UltraFlask™ Speed 500ml?
The Speedfill cap can come undone when stored inside a pack without the filter top — worth monitoring. Works with filter caps for backcountry use.
More from SoCalTrail Events's What we saw at the Bulldog Ultra
View SoCalTrail Events's expert gear recommendations on Rendezvu
What other hosts are saying
9 experts recommend the HydraPak UltraFlask™ Speed 500ml.
So many flasks, so much water!
Recommended in Cocodona 250
I usually put my filter top on this 500 ml soft flask. With good planning and a filter, I am usually fine with 1 L total water capacity on most of my trips (two 500ml soft flasks). One thing to be mindful of if you are not using the filter cap and are storing this in your pack is that the Speedfill cap can come undone!
Recommended in Fastpacking
Ben Corwin, Hutkeeper and mountain adventurer
Easy to fill and designed to fit a wide variety of pockets, we use these flasks for water and electrolyte drinks alike on long runs. Generally carry two, both up front, but sometimes one is enough if it's not too hot as there is quite a bit of available water on the Leadville 100 course.
Recommended in Teton Crest in a Day
I rec getting the 600ml for longer runs in the mountains
Recommended in Twisted Fork 68km
Best soft water bottles for carrying on the trails
Recommended in 10 Products I Actually Use
I use these bottles for every run, race, and adventure! They limit the "slosh" feeling and don't bounce around. The snap bottle really helps with easy re-fueling.
Recommended in 10 Products I Actually Use
the best soft flasks in the game. aid station volunteers are blown away when i roll up with these bad boys
Recommended in Pinhoti 100!
Paired with the long straw
Recommended in Race day Essentials
