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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 Stars76%
  • 4 Stars18%
  • 3 Stars5%
  • 2 Stars1%
  • 1 Star0%
4.68 / 5 based on 764 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 982 Q&A

Hydro Flask 21oz. Standard Mouth Insulated Stainless Steel Water Bottle
Hydro Flask 21oz. Standard Mouth Insulated Stainless Steel Water Bottle
Reviews (764)
Q&A (109)
Media (33)
Leave a Review
Anne-liese G.
Boulder , CO
19 reviews
I love my hyrdroflask! I have had mine for a little over 2 years now and its still going strong! I was very careful with it for the first few months as i am with most new products but now im pretty rough on it TBH and its still holding up beautifully. I have noticed some cracking and chipping of the colored layer around the base but not nearly as much as i would have expected. This keeps my drinks cold, ice i put in before bed will still be there when i wake up in the morning, and my teas hot for multiple hours! I highly recommend a hydroflask!
Tracy G.
Clearwater, FL
260 reviews
Fitspiration Expert Level 1
Hydro Flask is a great product for the first year. After that my ice stopped lasting overnight I had to refill it more often. It remained sweat-proof so that was great but the beverage staying cold for a long time was one of the main reasons I purchased it but with the amount of water I drink I found myself having to reice the bottle multiple times throughout the day when I would refill it with water. I think the cheaper Brands actually work just as well and since it needs to be replaced every year or so it's probably best to just go to Costco and get the non name brand version.
Natalie D.
21 reviews
Keeps my water ice cold, no matter how hot it is outside. It's such a relief to find a water bottle that keeps my water cold FOREVER! Plus it's so fun to customize it by adding cute little stickers! For the every day use I get out of it, it's worth the price. You do have to be careful not to drop it or else it will get dented, but mine has a small dent and hasn't had any problems with keeping my water cold. 
Tina F.
San Diego, CA
101 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.
Riley B.
Eagle Point
130 reviews
I love this water bottle! I use it everyday and besides the few dents from dropping it it has not shown the wear. At one point I did drop it and crack the lid, but I just emailed the company and they sent me a new one! Fantastic product and even better costumer service from the company!
Meri Y.
La jolla, CA
167 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.
Abby N.
Ventura, CA
127 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.
Sara H.
Northridge, CA
55 reviews
I love my Hydro Flask. A lot of companies are trying to replicate it, but I think Hydro Flask has been around longest. It keeps drinks ice cold or smoldering hot for HOURS. Comes in many different sizes. They do tend to be pricey for a water bottle, but put the investment in because it is worth it. Be careful not to drop them. They can dent semi-easily. 
Bridgette M.
52 reviews
This hydro flask is the greatest. It does an amazing job of keeping your drink hot or cold. This container comes in multiple sizes and colors. It’s also super strong so it can take a bit of a beating. I highly recommend this product!
John B.
Twentynine Plams, CA
145 reviews
I won one of these in a touch football competition. It's definitely works to it's claims. I put ice on it every other day and just keep adding water to it. Hold water super cold for a full day at least. Never timed it out before
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
336 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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