HydraPak UltraFlask Speed (500ml or 600ml) - Collapsible Soft Flask Water Bottle for Hydration Vests and Running Packs with Easy Open Cap

One race in, and I'm in love. I have that common salomon vest, and had to replace the hydrapaks. These are bigger than what I had but still fit. Running with the straws was a mixed bag - I'm still working on the best way to keep them from bouncing around while also not being pressured to my neck. The access for a quick drinky drink was amazing. These also feel thicker than the Salomon version that came with my vest. These are worth the upgrade - though, I haven't tried other brands for a true comparison.

Love this! I use this in my running vest and it works really well. Doesn’t leak and is easy to clean. The straw was too long for where I like to wear it high up on my vest but I was easily able to cut it to the perfect length for me and fit the piece back on with no issues.

These are a life saver while out hiking. The pack light when not in use and also do a good job of keeping your drinks a little cooler than some other products I've used in the past. Quality made and very durable, no leaks at all after months of use.

These soft flasks have become my goto hydration setup for long distance trail running. I love the size, the ability to pop the bottle open without unscrewing the top, and the bite valve. I think they are the best hydration option I've used. But they aren't 100% perfect. The bite valves seem to hold onto liquid, so you really need to pull the entire hard plastic piece out of the bite valve to wash it. Otherwise, even after a thorough cleaning, you'll still have just a bit of liquid hydration stuck in there. Even that is not too bad, but the hard plastic piece doesn't really nest into the bite valve when you put it back in. I'm always worried that will result in leaking. Along the same lines, some of the Hydrapak bite values lock into place, and some doesn't. (I don't use the extenders; they are too tall for me.) This one does not. So one time out on the trail, as I was drinking, the entire valve popped off, wasting a decent amount of liquid and getting my shorts wet. Not ideal, and it could actually be dangerous to lose liquid in certain situations. But if you keep that possibility in mind, the valve does stay on pretty much all the time. It's not a failure by any means. I'm glad Hydrapak are taking the low hanging fruit for hydration flasks. I just hope they make a couple of other changes to make it a perfect bottle.

Better than any name brand I’ve tried. Easy to snap open and close, easy to clean, doesn’t leak.What else do you want??

I finally upgraded from the standard sized 500ml flasks and appreciate the extra 100ml here as well as the wider opening for refills. Has made aid station visits a lot easier on the couple long races I've used it at so far. So far, no issues with leaking or durability and it feels great in the hand - I will regularly run for many miles just carrying one of these instead of throwing them in my backpack.

Leaking cap. Poor quality control.

Great addition to son's collection and they were used in the cocodona 250. Perfect size, sturdy product and worked well for the race.