Slide the Salomon Soft Flask 500mL/17oz 42mm into a compatible running pack and enjoy convenient hydration on the run. The Soft Flask uses safe and reliable BPA-free materials in a small, collapsible design that shrinks as you go to eliminate any water sloshing and keep you focused on the run ahead. With its wide opening, you can quickly and easily fill the Soft Flask, while a high-flow valve releases fluid faster to keep you hydrated without any fuss.