The days of rigid water bottles are long gone in trail running. Our convenient flexible Ergo Flask combines practicality with efficiency & ergonomics to make hydration easy. The smooth outer surface & an updated slimmer shape allow the trail running flask to be slid easily into a bag trail belt or pack. The wide opening helps to fill quickly at aid stations during a race saving precious seconds. Guaranteed leak-proof the flask shrinks as the liquid disappears preventing sloshing & taking up minimum volume when empty. The fast-flow bite valve is intuitive perfect when your attention is focussed on the trail underfoot. A second cap with a long drinking tube is provided as an option for those who prefer to drink without removing the flask from their pack. Eco-friendly & durable the flask is guaranteed 100% PVC & BPA-free so you can safely use it wash it & use it again. Simply put it in the dishwasher for easy cleaning when you get back home. KEY BENEFITS Wide opening for fast & efficient filling at aid stations combined with intuitive bite valve for easy drinking Reduces volume as it empties: the flask shrinks as you drink to avoid annyoing sloshing noises & taking up excess volume when empty Extra-long tube with drink valve supplied along with the standard cap allowing for easy drinking without removing the flask from a trail vest