The Pro Run Hydration 500ml (17oz) Flask keeps you fueled during training and race day. Its ultralight, collapsible design shrinks as you drink for easy storage, while the ergonomic shape ensures comfort on the move. The enlarged opening and bite valve enable quick refills and smooth flow. Leak-proof and soft, it pairs perfectly with the CEP Hydration Belt—ideal for steady hydration on long runs and endurance sessions in any climate.