This hydration bladder (2 Liter) uses food grade, highest quality anti-bacterial materials. Thick TPU water bag material is pressure & wear resistant. Stay hydrated whether you are on a hike, on a bicycle, or skiing down your favorite ski slope. Best for all high adventure uses outdoors when portable water storage is needed. Easily accessible shutoff valve prevents dripping when stored with water inside the pouch, or during rigorous activity such as cycling on a mountain bike, running or jogging, rock climbing, etc.