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 of the 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.