Hydro Flask Standard Mouth Water Bottle with Flex Cap 21oz/621ml
Hydro Flask Standard Mouth Water Bottle with Flex Cap 21oz/621ml
Hero image 0 of Hydro Flask Standard Mouth Water Bottle with Flex Cap 21oz/621ml, 0 of 4
HYDRO FLASK

Hydro Flask Standard Mouth Water Bottle with Flex Cap 21oz/621ml

4.4 stars out of 28 reviews
(4.4)|
28 ratings
Hydro Flask Standard Mouth Water Bottle with Flex Cap 21oz/621mlHydro Flask Standard Mouth Water Bottle with Flex Cap 21oz 621mlHydro Flask 21 oz Standard Mouth w Standard Flex Cap WhiteHydro Flask 21 oz Leak Proof Sports Water Bottle Standard Mouth StoneHydro Flask Standard Mouth Water Bottle with Flex Cap Black 21oz 621ml

Key item features

TempShield double-wall vacuum insulation keeps drinks cold up to 24 hours, hot up to 12 Flex Cap is leakproof when closed Honeycomb Insulated Cap for maximum temperature retention Made with 18/8 pro-grade stainless steel for durability, pure taste and no flavor transfer Color Last powder coat is durable, sweat-free and colorful BPA-Free Dishwasher safe Not for use on a stove, in a microwave or freezer
Price when purchased online
Not Available

How do you want your item?

How do you want your item?
Not available
Report an issue with this seller

About this item

Product details

Directions

Customer ratings & reviews

4.4 out of 5 stars
stars28 ratings15 reviews
How item rating is calculated
  1. 5 stars71% (20)
  2. 4 stars14% (4)
  3. 3 stars4% (1)
  4. 2 stars0% (0)
  5. 1 star11% (3)

Customer images

Filtered and sorted results would be available on the new 'Customer ratings & reviews' page.
Sort by |

Showing 1-3 of 15 reviews

Jul 20, 2025
anonymous
Item details
Color: Black
Sold bySyco DealsDelivered byWalmart
5 out of 5 stars review

Verified Purchase

I recently got the HydroFlask Standard Math Water Ball, and it's honestly one of the best bottles I've owned. Right out of the box, the design stood out — the math-themed graphics are fun, smart, and a great conversation starter. The build quality feels premium, with a solid stainless steel body and a powder-coated finish that resists scratches and sweat. I've been using it daily, and it keeps my water cold for over 12 hours easily, even when I'm out in the sun. The leak-proof lid gives me peace of mind when tossing it into my bag, and the wide mouth makes it super easy to clean or add ice. I also love how easy it is to grip, and the size fits well in my backpack's side pocket. The only downside is that it's a bit bulky for smaller car cup holders, but that's a small trade-off for how well it performs. Overall, I'd definitely recommend this to students, gym-goers, or anyone who wants a unique and reliable water bottle with some personality.

Incentivized Review
Helpful?5TBOCOLBTR38374690477
Jul 30, 2025
anonymous
Item details
Color: White
Sold bySave On PrimeDelivered byWalmart
5 out of 5 stars review

Verified Purchase

Cold All Day, Built to Go

I've been using the Hydro Flask 21 oz Standard Mouth, and it's been great for keeping my drinks ice-cold all day—ice usually lasts until the evening. I like that it never sweats, so I can toss it in my bag without worry. The Flex Cap is easy to twist on and off, though I'm not a huge fan of the exposed mouthpiece. It fits perfectly in my car's cup holder and side pocket of my backpack. It's tough, but I did get a small dent after dropping it—still works perfectly though.

Incentivized Review
Helpful?5TBOCOLBTR38374690477
Jan 4, 2026
Nikki
Item details
Color: Black
Sold bySyco DealsDelivered byWalmart
5 out of 5 stars review

Verified Purchase

Great for my daughter to use and it kept ice in it all day

Incentivized Review
Helpful?5TBOCOLBTR38374690477