500ml flask The Ultra™ Handheld features a 500ml/17-oz Quick Stow™ flask that molds to the shape of your hand. The 3D ventilated mesh material is comfortable and breathable over the long haul, and the integrated phone pocket has a zippered closure for added security. The elastic X-Grip strap system ensures a stable carry, and there's even reflectivity and an extra stretch pocket for additional gels or trash. 500ml/17oz Quick Stow™ flask is lightweight, collapsible and features our classic one-piece silicone bite valve for rapid hydration 3D ventilated mesh offers multi-directional airflow and cushioning to maximize comfort and breathability Elastic X-Grip strap system lets you customize your hold and keeps the flask secure even when your grip is relaxed Secure phone pocket - conveniently located with a zipper closure for secured quick access Reflectivity - for early morning or late-night runs Small stretch essentials pocket for extra fuel
