The ThermoBak Hydration Pack is CamelBak's original design, improved over the last two decades through battle-testing by troops around the world. Its 500 denier Cordura fabric is built to resist wear and damage effectively, and the insulated hydration reservoir pocket is lined with a protective layer of closed cell foam. It features a set of removable shoulder straps that can be stored inside the back panel, as well D-rings for direct attachment to a tactical vest or pack. It contains a large but lightweight 100 ounce Antidote reservoir equipped with a QuickLink Exit Port and HydroLock Bite Valve Adapter for rapid access and leak-free use. The extra-large filling port makes it easy to refill the reservoir, and can be accessed without removing it from the backpack for additional convenience.