HANDS FREEErgonomically-designed hand-strap provides grip-free comfort, and maximizes running efficiency. Breathable wicking mesh under hand position provides superior grip while the ExoSpine™ creates superior hand feel and support for the soft flask.MULTIPURPOSE18oz. BPA-Free soft flask with bite valve can be easily removed from sleeve and used in NATHAN hydration vest pockets. 18oz / 535mL BPA-FREE soft flask with bite valve The rigid ExoSpine™ for superior hand feel and support Ergo-designed hand strap provides grip-free comfort Breathable wicking mesh underhand position provides grip Small stash pockets for gels or a key Soft flask can be easily removed from sleeve 60% Nylon, 10% Spandex, 30% Polyester Storage Capacity: 15.25 cu in/0.25 Liters Weight With Bottle: 3.2 oz/91 g