Cascade Designs Platy Water Tank 4L - Having a few extra gallons of water around just makes things easier. Unfortunately, having a giant, empty container around doesn’t. Therein lies the beauty of our Water Tanks. Collapsible by nature, they pack flat for efficient packing and our Big Zip™ opening makes filling and cleaning a breeze. The biggest, 6L tank weighs a mere 4.4 oz (124g), making it just as practical for group backpacks and river trips as it is for summers on the road. New features include our new, more durable film, a lower, more stable design and reinforced handles for easy carrying.