Osprey Dyna 1.5 Hydration Vest with Reservoir - Small/Medium - Women's Trail Running - Hydration (Purple Storm)Training, racing and more. The Dyna 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 womens specific 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