Training, racing, and more. The Duro 1.5 is a svelte hydration companion perfect for training runs, long races, or streamlined days in the mountains. While it may be the smallest volume vest-pack in this series, it will carry you further than you ever imagined. With a body-hugging fit that provides bounce-free carry, smart and accessible organization for fuel and gear, and an included Hydraulics® LT 1.5L reservoir that can be supplemented with soft flasks, the Duro 1.5 helps you focus on what matters most: continuous forward motion.