Hydration on the go.
They're pretty much the perfect pair—our 21 oz Standard Mouth Bottle and our insulated Sport Cap. Together, they're your go-anywhere hydration companion. 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.

TempShield™
Our unique double wall vacuum insulation protects temperature for hours. Cold drinks stay icy cold and hot drinks stay piping hot so you can stay refreshed for any adventure.

Pro-Grade Stainless Steel
Made with 18/8 pro-grade stainless steel to ensure pure taste and no flavor transfer - and the durable construction stands up for whatever life brings.

Proprietary Powder Coat
Our proprietary powder coat means an easy-grip, sweat-free, and extra-durable bottle that you can take anywhere.

Lifetime Warranty
We stand behind our products.
Hydro Flask guarantees this Hydro Flask product with a limited lifetime warranty against manufacturer defects.
Product Benefits
- Versatile, middle-of-the-road size, equipped with our insulated Sport Cap
- TempShield™ insulation eliminates condensation and keeps beverages cold up to 24 hours and hot up to 12 hours
- Durable 18/8 Pro-Grade Stainless Steel construction
- BPA-Free and Phthalate-Free
- Compatible with our Standard Mouth Flex Cap
- Lifetime Warranty
- Sport Cap is not intended for use with hot liquids and is not leakproof
Size & Dimensions
21 oz | |
---|---|
Volume | 621 mL |
Mouth Diameter | 1.91" |
Diameter | 2.87" |
Height | 10.4" |
Weight | 11.3 oz |
TempShield™
Our unique double wall vacuum insulation protects temperature for hours. Cold drinks stay icy cold and hot drinks stay piping hot so you can stay refreshed for any adventure.

Pro-Grade Stainless Steel
Made with 18/8 pro-grade stainless steel to ensure pure taste and no flavor transfer - and the durable construction stands up for whatever life brings.

Proprietary Powder Coat
Our proprietary powder coat means an easy-grip, sweat-free, and extra-durable bottle that you can take anywhere.

-
Lifetime Warranty
We stand behind our products.
Hydro Flask guarantees this Hydro Flask product with a limited lifetime warranty against manufacturer defects.
Details & Specs
Product Benefits
- Versatile, middle-of-the-road size, equipped with our insulated Sport Cap
- TempShield™ insulation eliminates condensation and keeps beverages cold up to 24 hours and hot up to 12 hours
- Durable 18/8 Pro-Grade Stainless Steel construction
- BPA-Free and Phthalate-Free
- Compatible with our Standard Mouth Flex Cap
- Lifetime Warranty
- Sport Cap is not intended for use with hot liquids and is not leakproof
Size & Dimensions
21 oz | |
---|---|
Volume | 621 mL |
Mouth Diameter | 1.91" |
Diameter | 2.87" |
Height | 10.4" |
Weight | 11.3 oz |
Reviews/Q&A
Reviews
Q & A
- 21 oz Standard Mouth w/ Sport Cap is rated out of 5 by 341.Rated 5 out of 5 by fdgysuj from sport cap it works great for my soccer games ,but it makes me need to use the bathroom becuae i drink too muchDate published: 2019-12-04Rated 5 out of 5 by Justickles from Great quality! This product is exactly what I hoped it would be. Cold water for hours! Love itDate published: 2019-11-22Rated 5 out of 5 by Clarke from Great water bottle I bought one and went to Disneyworld and it kept all of my water cold the whole dayDate published: 2019-11-20Rated 5 out of 5 by Nonofurbeezwax from Awesome cap Bought for daughters soccer games and works great for a grab and go situationDate published: 2019-11-17Rated 5 out of 5 by Anonymous from Works great! I bought this for my daughter so she could have a cold drink all day at school and at dance it works great! She can fill it with ice in the morning and still has ice that night! I’m thinking of ordering one for myself!Date published: 2019-11-12Rated 5 out of 5 by bevfredc from Water is Ice Cold This is the only bottle I have ever owned that keep water ice cold for days. Before long trips, I fill it with ice. As I drink the water, I just add more and it is cold for days!!!Date published: 2019-11-06Rated 5 out of 5 by Erikcamac1212 from Really cool I bought this a month ago and it works great! Keeps the water cold.Date published: 2019-11-02Rated 5 out of 5 by The one and only girl from My Awesome Hydro Flask It’s a nice and bright color! Keeps water cold forever. The sport top is great. Great product!!!Date published: 2019-10-31Rated 5 out of 5 by Lala23 from My hydro flask I got my hydro flask in the mail and I loved it and the colorpDate published: 2019-10-26Rated 5 out of 5 by Taytortot58 from Amazing Job I bought this a week ago and I thought it would be amazing!!!! It washes easily, and it so so fun to drink out of!!! Can’t wait to order another one!!! Hope others will be inspired by this review and get one too!!!!Date published: 2019-10-21Rated 5 out of 5 by RonD from Lives up to the hype! Now I'm drinking more water. Next one will be larger with a straw lid. No regrets.Date published: 2019-10-20Rated 5 out of 5 by Sua2019 from Green Features I got my first one at REI and it is great I take it everywhereDate published: 2019-10-19Rated 5 out of 5 by Laxdad from I oop Bought for teen pax player because he “wanted to stay hydrated” at school. Having owned a Hydro flask for several years now I knew how awesome they were and thought how responsible of this young athlete. Little did I know he was trying to get a scrunchie from a VSCO girl... skskskDate published: 2019-10-19Rated 5 out of 5 by Butterfly12 from Awesome color red My son purchased this and he absolutely loves it!!!Date published: 2019-10-12Rated 5 out of 5 by madblade from the greatest water bottle to exist I bring this with me every where I go!!! It is perfect for any drink! Plus the color is so cute!Date published: 2019-10-11Rated 5 out of 5 by Anada from Love it!! Perfect size for an everyday bottle. I like the sports kid a lot, though u forgot that it does leak. Great product!Date published: 2019-10-08Rated 5 out of 5 by lovemywater from Love the water bottle and color! I was apprehensive about purchasing this water bottle based on price. However, I am very pleased with it! It keeps my water ice cold for hours on end, and I’m the color is vibrant and cool. I highly recommend the sport cap too. Never leaks and makes drinking easier.Date published: 2019-10-07Rated 5 out of 5 by J Rock from Best water bottle ever! This is the best water bottle I’ve ever had, however everybody in school makes fun of me for having it... saying I’m a “vsco girl”. I don’t even know what that means.. I’m a guy!Date published: 2019-10-03Rated 5 out of 5 by Manal from I love it I bought it a month ago and I love it. I’ve started to drink much more water since getting my hydro flask.Date published: 2019-10-03Rated 5 out of 5 by Shalanda from My daughter absolutely loves the flask This was a birthday gift for my daughter! We purchased the yellow color flask and the color is very sunshine and beautiful.Date published: 2019-09-29
Can I order this bottle but with the flex-cap? I noticed that they don't offer the 21oz Standard Mouth w/ flex cap in the "frost" color.
The 21oz standard flask that comes with the flex cap is currently out of stock in the color Frost. Please contact customer service at 888-584-9376 to discuss this further.Date published: 2019-10-30My bottle has a rattle has something broken inside?
The rattle you hear is a small metal disc that sits between the double wall of your flask that aids in the vacuum insulation process. If the disc becomes dislodged, you’ll hear a small gritty noise or rattle. This will not affect the insulation or structural integrity of your flask.Date published: 2019-10-30Is the sports cap easy to open? My mom has arthritis and is looking for a water bottle she use easily.
When the sports caps are brand new, they can be a little hard to open and close. I would recommend a wide mouth flask with a straw lid.Date published: 2019-10-29what lids can be used with this bottle besides the sports cap and the flex cap?
The Standard Mouth Sports Cap and the Standard Flex Cap are the only caps available for the standard mouth flasks at this time.Date published: 2019-10-27Are you able to put ice cubes in the standard mouth bottle or is it to narrow for ice cubes to fit through the top?
Normal sized ice cubes will fit in the standard flask.Date published: 2019-10-27So this bottle works w both the sports cap and the standard sized screw able lid?
YesDate published: 2019-10-27Can anyone recommend a bike cage for this bottle? I tried a plastic one to hold the bottle but the bottle was too heavy for the plastic and broke. I now have a metal cage but the metal on metal makes a lot of noise while riding my bike.
We regret to inform you that our products are not specifically designed to be carried in bike cages and they have not been tested for such use. We would be concerned about the possibility of the cage causing scratches, chips, and dents to your flask from improper fit and jostling. Therefore, we do not recommend carrying Hydro Flask products in bike cages.Date published: 2019-06-07Is anything being done about the leaky sports lid? I wanted to get one for my husbands birthday.
If the cap starts to leak, we'd be happy to replace your cap for you under our Lifetime Warranty. You can fill out a warranty claim here: (http://www.hydroflask.com/warranty/)Date published: 2019-06-06