Your perfect travel companion. Keep life moving with the Hydro Flask® Standard Mouth With Flex Cap 21oz. 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. TempShield™ insulation eliminates condensation and keeps beverages cold up to 24 hours and hot up to 12 hours. BPA-Free. 21oz. Hand wash only.