CamelBak updated its tried-and-true Classic Hydration Pack with a host of new features to ensure that you get the hydration you need when you hit the road or the trail. The new Antidote reservoir includes a lightweight, quick-seal cap that can now be filled without having to remove the reservoir from the pack, as well as pleating that allows the 2-liter bladder to maintain a low profile even when full. With an external stash pocket and a bungee that holds an extra layer, youAAAre set for a 2-hour adventure.