Keep life moving with our 21 oz Hydroflask bottle and Standard Flex Cap. It stashes easily into a small shoulder bag, your pack’s side pocket, or your car cup holder, and holds enough ice cold goodness to keep you going for hours without weighing you down. No wonder it's one of our bestselling water bottles. 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.

Versatile, middle-of-the-road size
Designed for everyday use on the trail, in the car, at the office, and at the gym.
Stays Hot up to 6 Hours
Stays Cold up to 24 Hours
The Standard Mouth fits all shapes and sizes of ice cubes, yet is still small enough to drink from on-the-go, stuff in a pack, or nestle in a car cup holder
Compatible with the Hydro Flask Standard Mouth Insulated sport cap.
Equipped with the Hydroflask Standard Mouth Bottle Cap

The Hydro Flask Difference

TempShield Double Wall Vacuum Insulation
18/8 Pro-Grade stainless steel
BPA-free and Phthalate-Free
Durable, Proprietary sweat-free powder coat finish
Lifetime warranty

Hydro Flask 21oz Standard Mouth Bottle