The Hydro Flask 21 oz Standard Mouth with Flex Straw Cap is the ultimate upgrade for easy, one-handed hydration. It combines the slim, cup-holder-friendly design of the 21 oz bottle with a convenient straw lid.
Flex Straw Cap: Features a reliable, leak-proof straw that allows you to sip without tilting the bottle. The flexible strap makes it easy to carry all day.
TempShield® Insulation: This signature double-wall vacuum insulation keeps cold drinks icy for up to 24 hours. (Note: Straw caps are generally not intended for hot liquids).
18/8 Pro-Grade Stainless Steel: High-quality steel construction ensures durability and prevents any metallic aftertaste.
Slim Profile: Specifically designed to fit into side pockets and standard car cup holders.
Color Last™ Powder Coat: Provides a slip-free grip and remains vibrant through the dishwasher and years of use.