Conveniently and comfortably carry just the essentials with you on your next road run with the Osprey Packs Duro 1. 5 Hydration Pack. Designed to make the most out of its small design, this true vest-pack provides bounce-free stability and utilitarian comfort as you crush miles on dirt, pavement, and everything in between. Tough nylon construction holds up against close encounters with rough surfaces and pesky, snagging branches, while the included Hydraulics 1. 5L reservoir with attached hose and sternum magnet frees up your hands for easy drinking when you're in the middle of a grueling, lung-busting ascent.