The ADV SKIN 5 makes it easy to access your essentials and accessories. An updated closure system, combined with the Sensifit construction, adjusts to your body shape precisely and quickly. It's the ultimate solution for demanding endurance runners. Hydration The integrated soft flasks make it easy to drink as soon as you feel thirsty, and stays balanced when you run, so you can push the limit and stay hydrated. Freedom of movement The Sensifit construction offers a snug, precise, comfortable fit and balances the load front and back, so you can move more freely and faster. Ease of use The components of this pack are easy to use, and offer different ways to adjust the fit and carry poles and accessories.