Featuring the same great hand-feel, this slosh reducing, super-efficient handheld now features insulated hydration to keep runners cooler, longer. 18oz / 535 mL BPA-FREE Insulated Soft Flask with bite valve Insulated properties keep fluids cooler 38% longer than non-insulated soft flasks The rigid ExoSpine™ for superior hand feel and support for the soft flask Ergo-designed hand strap provides grip-free comfort, and maximizes running efficiency Soft flask can be easily removed from sleeve, and used in NATHAN hydration vest pockets Breathable wicking mesh under hand position provides superior grip Expandable stash pocket for small items or nutrition Storage Capacity: 8.5 cu in/0.14 Liters Weight With Bottle: 3.2 oz/91 g