The Ultimate Direction Women's Ultra Vesta Running Hydration Vest offers increased hydration capacity and roomier front storage, all while weighing less than its predecessor. This hydration vest fulfills the needs of athletes crushing distance runs, ice climbs, and demanding hikes in the backcountry. Two fully collapsible Body Bottle 500s (17-ounces each) keep you hydrated during intense efforts. Plus, it easily accommodates a two-liter reservoir within its large front compartment for extra hydration capacity on the hottest days of the year. There's also a mesh pouch for partitioning wet gear and clothing from the rest of the pack. Adjusting precisely to conform to your upper body, the side-adjustable shoulder straps and sliding rail sternum straps provide a fine-tuned fit when you're moving fast. Moisture-wicking material along the shoulder straps and back panel prevents perspiration build-up, which is especially important when you're pushing your physical limits in stifling weather. Other run-friendly features include drop-in pockets along the shoulder straps for easy-access to energy gels and trail snacks.