Hydrapak Soft Flask 150ml Whether it's running trails, paddling rivers, or hitting the slopes, keeping fueled up and hydrated is just a bite away. The collapsible, lightweight Hydrapak SoftFlask 150 Simpler, faster and cleaner than carry 5 Gel.  This lightweight 150 ml collapsible gel flask allows for instant nutrition on your most challenging expeditions. Just fill it with up to 5 gel servings.  It can be integrated into a variety of running packs, run vests, waist belts, even PFDs.