Hydro FlaskStandard Mouth Bottle with Flex Cap

The tight neck on this thermos really holds the heat in. It keeps boiling water hot for at least 5 or 6 hrs. Cold things stay cold longer than that. I like how easy it is to clean with a bottle brush. The cap is a great design. One thing I’m weary of is hollow caps that allow liquid in. Had a bad experience with other brands. This one isn’t like that. It’s high quality and just uses a rubber gasket to seal.

I’m tempted to write a review defending a company I have no vested interest in from one star raters complaining about how it “dents too much too fast” and “it’s expensive but all it does it keep my water cold” (as if they were forced to buy it), but as someone that uses his gear hard and often and has also waited a while before submitting a review on purpose, I will share what really matters about this bottle and the reason you should buy it.It keeps water cool for at least a day, even while sitting in a hot car in the middle of a Texas heatwave. It works, even if you drop it multiple times while out and about and dent it. It’s a tool to keep your fluids cold, not a fashion accessory. If it must be visually appealing to you, then try your best not to drop it as it is made out of thin metal walls gapped only by air for the sake of both keeping weight down and working as intended. Pictures provided to show just how dented mine is after countless drops, which in my opinion seems like less wear than I would’ve expected given the abuse this thing sees.

Cool color and came in on time.The 21 oz bottle is perfect for me because I needed something that wasn't as bulky as my other 32 oz wide mouth Hydro Flask.

Keeps hot hot and cold cold

I’ve really enjoyed this water bottle. Holds the cold for a long time. Haven’t tried hot in it. Easy to hold.

I use this bottle at the gym. It's easy to carry around and not bulky. I see people carrying around larger bottles but they seem like overkill. My only wish is that the top was a sipper top so taking a drink is less involved.

the Hydro Flask water bottles are always the best!!!

Beautiful, useful, keeps cool all day

El material es de muy buena calidad

Solide, très jolie, compacte.. Conserve la fraîcheur vraiment très longtemps.Par contre 650ml c'est pas beaucoup, on retourne souvent à la fontaine la remplir, si on est un gros buveur.

Item arrived damaged.

Belle qualité

I purchased the Hydro Flask Water Bottle 621 ml after reading many wonderful reviews. Hydro Flask promises durability and resistance and keeping beverages cold up to 24 hours and hot up to 12 hours when using the lid.At first, the bottle kept the temperature of the drinks perfectly. Unfortunately, a few weeks after I started using it, the bottle fell from around 40 cm high: the paint chipped awfully and the so-resistant bottle was dented. Not a good start. A few more weeks passed and I noticed that the so-renowned "tempShield double-wall, vacuum insulated technology" was no longer working that well, as the bottle no longer keeps the temperature of the beverages as promised and guaranteed by Hydro Flask.The colour of the bottle is very nice and the matte finish of the paint looks smart.All in all, I would say it is a good bottle, but my experience with it has not been better than with my KollyKolla bottle, which only costs a portion of the Hydro Flask's price.