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

BY HYDRO FLASK #2 in Water Bottles

4.7 out of 5 stars
  • 5 Stars77%
  • 4 Stars17%
  • 3 Stars5%
  • 2 Stars1%
  • 1 Star0%


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...

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Hydro Flask 21oz. Standard Mouth Insulated Stainless Steel Water Bottle
Hydro Flask 21oz. Standard Mouth Insulated Stainless Steel Water Bottle
Reviews (854)
Q&A (127)
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Austin, TX
13 reviews
This is a must have for everyday travel. I have both the 21oz & 32oz that are, to me, the perfect combo. It’s great having this one which fits my vehicles cup holder and is also easy to carry on a day hike. Cold water stays cold for the majority of the day - less than the larger flasks but still good enough for mosts hot summer days.
Los Angeles
34 reviews
I take this bottle with me absolutely everywhere. It does such an amazing job keeping my water cold and I've even used it for tea & it worked perfectly. It is also a fantastic way to practice sustainability and avoid the issues that can come with single use plastic. I would definitely recommend this bottle to anyone.
Las Vegas, NV
41 reviews
I take this water bottle with me everywhere, I absolutely love it. The size is perfect and it's easy to carry. I love how it has different colors. The water stays so cold for days. Even though it is a bit price I would still recommend it to everyone I know.
14 reviews
I’ve never loved anything like I love my hydroflask. I never wanted to be one of those girls talking about how the ice never melts - but here I am. I take this thing with me everywhere, and it’s so much better for the planet than those plastic ones!!
los angeles
24 reviews
I cannot go anywhere without my flask. Keeps my water super cold even when I leave it inside my car on a hot day. Worth every penny and I love that I no longer use plastic water bottles. Only downside is the exterior can get a bit scratched.
18 reviews
Hydro Flasksksksks and I oop! They are a great company and can keep things cold or hot for a really long periods of time. They also are perfect sizes and have a variety of color. They are also really easy to clean. A 100 stars out of 5.
Los Angeles
11 reviews
Water is so essential in our everyday lives and this water bottle is such a life saver! It keeps water cold for a loooong time (but let’s be real, I never keep water in there long enough 😂) and it’s stylish!
Gretna, LA
616 reviews
Love my Hydro Flask!! It’s the perfect accessory for a hot summer day, or any day! Very portable, and I love the variety of colors. Staying hydrated never felt more colorful! Loving anything canteen and tumbler lately
Corvallis, OR
108 reviews
LOVE this hydro! I love this brand! Oregon designed! It keeps ice cold at least 10 hours and things hot for at least 8 hours from experience. I'm sure longer but that is my personal test. It does dent when you drop it. I have mine covered in stickers and it is super personalized to me.
Kansas City
15 reviews
I will always be recommending hydro flask. Their products are amazing. I have one of this size and two of the 40oz size. They keep water cold and even ice still frozen for more than 20 hours. They’re great if you’re going to be gone all day or going on a run!
Colton, CA
356 reviews
Is this water bottle expensive ?
Prairieville, LA
96 reviews
Austin, TX
340 reviews
Fitspiration Expert Level 3
Does it have good insulation? Is it too expensive? Or cheap with good quality?
Las Vegas, NV
113 reviews
How long does the water stay cold?

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