rnnr Soft Flask Bottles are soft, flexible, and built for long miles. Designed with welded construction to stay secure and leak-proof, these flasks slide easily into most hydration vests, belts, or pack pockets with a low-profile fit. As you drink, the flask collapses down to reduce sloshing and bounce, then packs away small when empty. Available in 500ml. Backed by our Lifetime Warranty—if anything goes wrong, we’ll repair or replace it. No stress, just run.