21 oz Standard Mouth

21 oz Standard Mouth White
21 oz Standard Mouth Citron
21 oz Standard Mouth Tangelo
21 oz Standard Mouth Kiwi
21 oz Standard Mouth Mango
21 oz Standard Mouth Pacific
21 oz Standard Mouth Plum
21 oz Standard Mouth Forest
21 oz Standard Mouth Graphite
21 oz Standard Mouth Lava
21 oz Standard Mouth Cobalt
21 oz Standard Mouth Stainless
21 oz Standard Mouth Black
21 oz Standard Mouth Mint

21 oz Standard Mouth

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Availability: In stock

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Shop Compatible Products
Shop Compatible Products:
  • Standard Mouth Insulated Sport Cap$6.95

    Standard Mouth Sport Cap-Black


  • Standard Mouth Loop Cap$3.95

    Standard Mouth Loop Cap-Black



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Hydration on the Go.

Our 21 oz is the perfect go-anywhere companion on your busiest days. It stashes easily in a small shoulder bag, your pack’s side pocket or your car cup holder, and holds enough to keep you going for hours without weighing you down.

    Unique Product Benefits

  • Easy to Transport
  • Versatile, middle-of-the-road size
  • Universal Benefits

  • TempShieldTM Protected
  • Keeps cold up to 24 hours
  • Keeps hot up to 6 hours
  • 18/8 Pro Grade Stainless Steel
  • BPA-Free and Phthalate-Free
  • Durable, sweat-free powder coat finish (or our Classic Stainless option)
  • Lifetime Warranty
  • Compatible with Standard Loop Cap and Sport Cap
21 oz Standard Mouth is rated 4.7 out of 5 by 40.
Rated 5 out of 5 by from Exceeds expectations! I was given a Hydro Flask a year ago and my immediate family slowly acquired a Hydro Flask for themselves. We all loved them so much that we got each family member for our reunion in Acadia National Park. Only regret is not enough colors in the larger jugs. I like "Matchy Matchy"
Date published: 2016-06-08
Rated 4 out of 5 by from Keeps my water icy cold but has one saddening flaw I love how well Hydro Flask keeps my water icy cold. It has a great look and feel to it. The one huge disappointment I just recently discovered from this amazing product is its durability. After only one fall from the kitchen table, my Hydro Flask has dented. It still holds water but I know with dents this will compromise its vacuum insulation and therefore lessen its capacity of keeping my water icy cold (plus its just sad to look at). Bottom line, I am so close to converting the whole family over to Hydro Flask but unfortunately, this tragic event was a rude awakening of its lack of durability (particularly with the item's higher ticket price compared to other water bottles).
Date published: 2015-10-03
Rated 5 out of 5 by from This was the size that sold me! This was the starter size for me that lead to my collection of all of the hydroflask sizes, except the 24oz (recently added, that's next).At first I bought this as a trial for my husband to take to work. He's a fuel truck driver on Oahu and the heat with humidity can make u sweat like crazy. He filled it up with half ice and water and he said it was wayyyyy better than the plastic frozen water bottles that he'd reuse all the time. Then he said he wanted a bigger size just for him. So I got him the 40oz n he said after 4 days it's not big enough so I got him the 62oz n he's been happy eversince. Me I had to get 32oz as the 21oz wasn't lasting me all day. But we still use the 21 when we gotta drive around alot as it's the only one that fits the standard size cup holder in our truck n we have the 64oz filled up ready to refill our 21. Bcuz of having access to ice cold water all the time. This product has helped us to lose weight alot and proud to say no more cotton mouth anymore. The reason I choose only this brand is their lifetime warranty, no one has this. I'll gladly pay the price for high quality and they keep their word too! I had 2 of my flasks returned using the warranty and had no problems since. As far as choosing btwn the stainless steel and the color. We ended up liking the one with color, the reason on is the heat. When u touch the stainless steel one and left iy in ur hot car, it's hot to touch but the ice is still there. When u do the same with the color one, its doesn't burn n there's grip to it. Like a sand kinda paint for it so it's not slippery like the stainless. My only little concern is having the larger sizes fit in the cup holder. But then again I understand the design would make it more expensive, besides other people makes holders, etc. so I can hang it from the neck part of my seat in my truck. Thank you Hydroflask for an awesome product. Sincerely, Da 808 couple!
Date published: 2015-08-02
Rated 5 out of 5 by from the BEST water bottle I have ever purchased I bought this a few months ago, and it comes everywhere with me. I cannot imagine using any other water bottle but this one. Cold water all day!!! And this particular size is great.
Date published: 2015-06-09
Rated 5 out of 5 by from My favorite water bottle ever! I bought one of these on a whim and I haven't stopped using it. I didn't abandon my other water bottles but I now use this as my main. In truth, I bring it with me almost everywhere now and it has actually helped me to become a more hydrated individual. The size is perfect and it fits right into the cup holder in my car. Water stays cool what seems like forever. The aesthetic of the sweat proof coating on the outside just seals the deal. I'm planning on buy one for each of my family members as future gifts.
Date published: 2015-09-21
Rated 5 out of 5 by from LOVE MY HYDRO FLASK!! I'm a teacher and lacrosse coach. I prefer to have ice available all day...quickest way to cool the body down. After a long hot day on the field and over a 48 hour period I had significant amounts of ice in my flask...with icy cold water to drink!! My current Hydro Flask was a gift, but I plan on purchasing several other items. P.S. My niece said I always have/ find great cool gadgets and technology. This is now the best, new thing I've ever had!! I use it everyday and I find I drink more water because it is icy cold. Thank You Hydro Flask & Thanks Kevin and Marissa for the Great Gift!
Date published: 2016-05-05
Rated 5 out of 5 by from I love my Hydro. I was given this as a gift, and it has been the best gift! One morning I made tea, and for some reason or another I didn't drink it in the morning. I was in my car and I looked down and saw that my hydro was in the cup holder. At that point I was sure my tea was cold, but I was thirsty. I took a sip and it was still hot! I was so pleasantly surprised! Ever since then, I carry my hydro everywhere. I have been trying to drink more water, and having my hydro has been the best thing for that goal. I love my ice water that will stay ice cold for the whole day! I am so about this product, I am looking into buying the 32oz and I know I won't be disappointed! #Godbless
Date published: 2016-04-08
Rated 4 out of 5 by from Not for trail use This bottle is GREAT for office use or delicate trail use. Fell out of my bag as I was picking it up and fell(less than 12 inches) now I have a pinky nail sized dent in the bottom. I love the bottle but I wish it was more durable. I would definitely recommend it for normal everyday use, just keep away from trail.
Date published: 2015-06-23
  • 2016-07-25T07:55CST
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Q & A

Which of these bottles would best fit in a mountain bike water bottle cage? 

Asked by: Biker Dude
We use the narrow mouth bottles on our bikes with the Sports Caps. They work great in hot weather. We did change out our bottle cages to be side loading (the 24oz bottles are tall) and synthetic (so they don't scratch up the bottles).
Answered by: Menetski
Date published: 2016-07-20

Does it fit standard cup holders ?

Asked by: Charles1
Does not fit in my Acura, nor Volvo, nor Toyota cup holders
Answered by: Yogasauce22
Date published: 2016-07-01

Can a standard mouth fit ice?

Asked by: Michie
It all depends on how big the cubes that you are trying to place in there. Yes some cubes will fit but not the big 2in cubes
Answered by: Anonymous
Date published: 2016-06-04

I have a hydro flask 21oz normal mouth with a sports mouth top there seems to be a check valve missing when u tilt the flask water comes out thanks  

Asked by: flojo
Hello, Thank you for sharing your concern with us! We are happy to help you out. Please visit our warranty page at hydroflask.com. There you can utilize our lifetime warranty. Cheers!
Answered by: Hydro Flask Customer Team
Date published: 2016-01-29

I have a green hydro flask that only holds ice for about 4 hours. My other colors of the exact same model can hold ice for more than twelve hours. Why is the green one unable to keep ice?

Asked by: Brooke
Check out our flask warranty: http://www.hydroflask.com/warranty/
Answered by: Hydro Flask Customer Team
Date published: 2016-01-26

What is the diameter of the narrow mouth? standard mouth? wide mouth?

Asked by: eggheade
The narrow mouth is 1 5/8 inches. Here is the link to all the others:http://www.hydroflask.com/frequently-asked-questions/
Answered by: Hydro Flask Customer Team
Date published: 2015-11-25

How can you tell if my Hydro Flask is real and not a fake?

Asked by: Oahu58
If you have concerns about your flask, please send a photo to info@hydroflask.com and we'll take a look!
Answered by: Hydro Flask Customer Team
Date published: 2015-11-18

What are the dimensions/specs for this water bottle? Looking for length, width, diameter.  Thanks!

Asked by: AppleStationTrail
For the dimensions of our products please check our FAQ page: http://www.hydroflask.com/frequently-asked-questions/
Answered by: Hydro Flask Customer Team
Date published: 2016-05-14
  • 2016-07-25T08:08CST
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