Brand: HydraPak

    Category: Running Water Bottles & Flasks

    Recommended by Tyler Sarkisian, Endurance / Strength Athlete + Coach — Salt Lake City, UT

    The UltraFlask™ Speed 500ml 2-Pack is designed for athletes seeking a lightweight, flexible hydration solution that fits seamlessly into their gear. With its innovative SpeedFill™ Cap and durable construction, this flask ensures quick refills and reliable performance during any activity. 1. Wide form design allows for easy handling and stability during use. 2. Constructed from lightweight TPU material, ensuring durability without added weight. 3. 3D welded bottom provides enhanced stability and prevents leaks. 4. SpeedFill™ Cap enables rapid refills, perfect for on-the-go hydration. 5. Soft and pliable structure allows for compact packing in most running vests and backpacks. 6. Each flask holds 500ml (17oz), ideal for extended outdoor activities. 7. Designed specifically for trail running, hiking, and other dynamic sports. The UltraFlask™ Speed 500ml 2-Pack is perfect for runners, hikers, and outdoor enthusiasts who require a reliable hydration solution. It excels in various environments, from rugged trails to urban runs, making it suitable for both casual joggers and seasoned athletes. Ideal for warm weather activities, this flask ensures you stay hydrated without the bulk, allowing for a streamlined experience during your adventures.

    Price: $31.2 - $39

    Who it's for
    Trail runners and ultramarathon athletes who carry water up front in a vest and need easy on-the-go refueling. Also suits backcountry users who pair it with a filter cap for lightweight water sourcing.
    What people are saying
    Hosts praise the low-slosh feel, vest-pocket fit, and compatibility with electrolyte drinks, with several carrying two simultaneously. One host recommends sizing up to the 600ml for longer mountain runs.
    Worth noting
    The Speedfill cap can come undone when stored inside a pack without the filter top — worth monitoring. Works with a filter cap, making it usable for sourcing water on trail.

    Frequently asked questions

    Who is the UltraFlask™ Speed 500ml 2-Pack for?

    Trail runners and ultramarathon athletes who carry water up front in a vest and need easy on-the-go refueling. Also suits backcountry users who pair it with a filter cap for lightweight water sourcing.

    What do experts say about the UltraFlask™ Speed 500ml 2-Pack?

    Hosts praise the low-slosh feel, vest-pocket fit, and compatibility with electrolyte drinks, with several carrying two simultaneously. One host recommends sizing up to the 600ml for longer mountain runs.

    What should you know before buying the UltraFlask™ Speed 500ml 2-Pack?

    The Speedfill cap can come undone when stored inside a pack without the filter top — worth monitoring. Works with a filter cap, making it usable for sourcing water on trail.

    More from Tyler Sarkisian's Trail Run

    View Tyler Sarkisian's expert gear recommendations on Rendezvu

    What other hosts are saying

    9 experts recommend the HydraPak UltraFlask™ Speed 500ml 2-Pack.

    Jeff Garmire, Athlete

    So many flasks, so much water!

    Recommended in Cocodona 250

    Meikael Beaudoin Rousseau, Professional Trail & Mountain Runner

    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

    Gavin Prior, Ultra Trail Runner

    I rec getting the 600ml for longer runs in the mountains

    Recommended in Twisted Fork 68km

    Brandon Pitzen, Outdoor Enthusiast

    Best soft water bottles for carrying on the trails

    Recommended in 10 Products I Actually Use

    Anne Hinman, Trail + Ultra Runner

    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

    Clare Farrow, ultrarunner

    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!

    Michael Whitfield, Trail Runner

    Paired with the long straw

    Recommended in Race day Essentials