Insulated Soft Flask with ExoSpine 18oz

Built for runners who want insulated hydration in their vest, the Insulated Soft Flask with ExoSpine™ 18oz is a large-capacity insulated soft flask designed to keep fluids cool over long efforts. Fits in front hydration vest pockets or in back storage for extra capacity on hot-weather runs and ultras.

The classic bite valve gives you control over flow, and it's fully compatible with all Nathan hydration vests.