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Hydro Flask 21oz. Standard Mouth Insulated Stainless Steel Water Bottle

BY HYDRO FLASK #5 in Water Bottles

4.6 out of 5 stars
  • 5 Stars75%
  • 4 Stars19%
  • 3 Stars5%
  • 2 Stars1%
  • 1 Star0%
4.67 / 5 based on 733 Reviews

Product Description

The 21 oz standard mouth Hydro Flask is ideal for taking on a weekend bike ride or hike to keep your fluids cold. Or take it up the mountain and have hot coffee, cocoa, or soup waiting for you at the end of the day. The Standard Mouth bottle features a larger mouth opening and is ideal for those who need to take in more hydration at a quicker pace. As with all Hydro Flask bottles, they fit perfectly in most car, bicycle, and stroller cup holders and water bottle cages. These water bottles were developed to perform in every environment. Each Hydro Flask is cast from double wall vacuum insulated food grade 18/8 stainless steel, therefore they are BPA-Free and resistant to bacteria and odors. The double wall vacuum insulation technology allows Hydro Flasks to keep contents hot for 12 hours or cold for 24 hours. see more...

Top Questions See all 968 Q&A

  • Does the water taste as good as glass?4 Answers
  • These look like they are pretty heavy. Are they? 11 Answers
  • Is this worth the high price tag? I want to get a bottle like thi...5 Answers
Hydro Flask 21oz. Standard Mouth Insulated Stainless Steel Water Bottle
Hydro Flask 21oz. Standard Mouth Insulated Stainless Steel Water Bottle
Reviews (733)
Q&A (105)
Media (34)
Leave a Review
REVIEWS
Ruth K.
192 reviews
I got this hydro flask for Christmas and it is my absolute favorite. It’s a great size for me and I have to say I love it more than my swell bottle. It’s super durable and sturdy. It doesn’t allow my water to spill when it’s rolling around in my purse. It’s versatile- I use it for work during my 12 hour days and also on hiking trips. I really have nothing bad to say about it. I would recommend this bottle over the swell bottle.
Tina F.
san diego
71 reviews
I love this! The best when you need to keep liquid hot or cold for hours! Awesome for hiking, camping or working out. I keep it at my work desk so I can remind myself to stay hydrated. I would definitely recommend this to anyone who is active like myself and does not want to contribute to the horrible plastic problem or waste money on buying bottles water.
Meri Y.
La jolla, CA
149 reviews
I love my hydroflasks! I love how they can literally keep ice water cold for over a day (the ice doesn’t melt much) and can keep hot drinks warm similarly. It’s a little expensive compared to other water bottles, but considering the lifetime warranty, I think it’s worth it.
Kay L.
467 reviews
I own several of these and love them! It keeps your drink warm and cold longer than any thermal flask I’ve owned! I had a bottle of boiling hot water in mine and accidentally left it in a freezing car overnight. When I opened it the next morning, the drink was still warm!
Abby N.
Ventura, CA
119 reviews
One word. Obessed!! I won a Hydro Flask at a festival I went to and didn’t really know what it was. I can put cold water in it and the water will stay cold all day. I love it! I take it everywhere I go. I also keep one at work and my husband has one as well and loves how the water stays cold. Definitely worth the cost.
Nicole G.
Kansas city, MO
318 reviews
This is a sturdy water bottle. It keeps cold water cold for over 24 hours and keeps warm things warm if you choose to do that. It saves the planet by avoiding plastic and doesn’t have that weird metal taste that don’t cheaper bottles have.
Vanessa H.
18 reviews
I LOVE MY HYDROFLASK. I’m in college so i sue it everyday and it’s literally the best water bottle ever! It keeps your drinks COLD and it doesn’t sweat! It’s easy to clean and store and let not forget about how good it looks!
Gina L.
386 reviews
Love my Hydro flask. It keeps my drinks warm for 24 hours. I put boiling hot water in my bottle and accidentally left it in my freezing car overnight. The next morning, I found that the water inside was still warm!
Belle B.
Matheny, WV
550 reviews
Fitspiration Expert Level 1
I have so many of theses, it’s an unhealthy. They just recently started selling them at Marshall’s/TJ Maxx/ Homegoods. So I definitely recommend buying them there because they are cheaper! Also these are amazing.
Christine T.
Edmonds, WA
31 reviews
I love this water bottle and use it daily at the gym. I don't ever drink water if it isn't ice cold so I thought purchasing this would be a good investment. It keeps my ice from melting for long periods of time. One time, I forgot my hydroflask overnight and my coworker found it the next day with ice still in it, over 15 hours later. He was so impressed he went out and purchased it also! It is pricey but it was worth it to me personally. I bought the 24 oz. rather than the 21 oz. because it was just a few dollars more at REI. I believe I paid around $30 for it and I got it in the color mango. I also don't prefer the twist off cap so I recommend purchasing the sports cap which was an additional $10. It makes it really convenient to just pick up my bottle and drink between my exercise sets. I have dropped it a few times over the past year since it goes through a lot of usage so it is a little dented and scratched up but that's not a big issue for me, I still love it.
Caroll S.
Colton, CA
354 reviews
Is this water bottle expensive ?
Kaleyha U.
Mansfield, OH
14 reviews
Do these keep cold
Jazmyn J.
Prairieville, LA
96 reviews
Is this a good water to bring to the gym? does it keep the drink inside cold enough?
Mary F.
Austin, TX
333 reviews
Fitspiration Expert Level 3
Does it have good insulation? Is it too expensive? Or cheap with good quality?
Cassidy C.
110 reviews
How long does the water stay cold?

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