Ultraflask, 600ml soft flask, 20 oz, by Orange Mud

Fits in back pack strap pocket

Easy to fill

Very durable

Love the Orange Mud gear! Fits so incredibly well.

Having two flasks in addition to the water is great for longer trips on the mtb.

I added these to my Endurance Hydration pack and use them to hold electrolytes (saving the big bladder for straight up water). They fit perfectly and didn't leak even a drop during a recent half marathon. Can't go wrong with these.

Great products. Fast shipping. Would buy from again for sure.

Overall I really like this. Compact, functional, no leaks, minimal sloshing due to how it shrinks as it empties. And as long as I rinse it immediately upon completing my run, it doesn't hold a residual taste of whatever beverage I last had in it. The only gripe I do have is minimal. Despite allegedly being designed with a removable straw, I was unable to remove mine short of cutting it. Instructions I've looked up online suggest simply pulling it out with a firm tug, but I've really pulled pretty hard on mine, to the point where I was concerned about possibly breaking the cap or permanently misshaping/damaging the straw, and therefore I resigned to using it only with the straw. I use mine in the front pockets of my Orange Mud Gear Vest Pro, and I find the straw to be a little long when the flask is full, as it kind of gets in the way of my turning my head fully without getting smacked in the chin by the bite valve, which is why I initially wanted to remove it, but once the fill level starts to get down to about half quantity I'm grateful to have the straw. So perhaps I'll end up having to simply shorten it by a couple inches instead of removing it entirely. Overall good product!