21 oz Standard Flex Straw Cap
Product details
Stay hydrated with ease using the Hydro Flask 21oz Standard Flex Straw Cap bottle. Built with TempShield® double-wall vacuum insulation, it keeps drinks cold for up to 24 hours or hot for 12. The leakproof Flex Straw Cap makes sipping effortless, while the 18/8 pro-grade stainless steel ensures durability, pure taste, and no flavor transfer. Featuring a Color Last™ powder coat finish, this BPA-free bottle is dishwasher safe, sweat-free, and designed to fit most cupholders—your go-to companion for work, workouts, and adventures.
- 21oz insulated water bottle with Flex Straw Cap
- TempShield® double-wall insulation keeps drinks cold 24h, hot 12h
- Leakproof straw cap when closed
- Made with durable 18/8 pro-grade stainless steel
- No flavor transfer, pure taste
- Fits most standard cupholders
- Color Last™ powder coat is sweat-free and long-lasting
- BPA-free and dishwasher safe
- Flex Straw Cap not for hot liquids
21 oz Standard Flex Straw Cap
Product details
Hydro Flask FAQ
Common questions about Hydro Flask
Learn more about what makes Hydro Flask unique.
What is TempShield insulation?
TempShield is Hydro Flask's double-wall vacuum insulation — it keeps cold drinks cold for up to 24 hours and hot drinks hot for up to 12 hours by eliminating heat transfer between the walls.
Which Hydro Flask size is right for me?
The 21 oz is ideal for short outings and fits most cupholders. The 32 oz is the all-day everyday choice. The 40 oz is best for long hikes, gym sessions, or anyone who needs to stay hydrated all day without refilling.
What makes Hydro Flask worth it?
Beyond the colour range, Hydro Flask pairs proven TempShield insulation with a durable powder-coat finish, a huge accessory ecosystem (straw lids, boots, slings), and a lifetime warranty — a stylish, leak-resistant bottle built to last for years.
Is Hydro Flask lead-free?
Yes — Hydro Flask has been proudly lead-free for over a decade, with no lead used anywhere in its construction, which is a deciding factor for many buyers comparing insulated bottles.
