These are 3 liter (100 oz) hydration carriers from Camelbak in desert DCU camo. The carrier is made of Cordura material for durability. Shoulder straps are adjustable and there are D rings for attaching accessories or to attach the carrier to kit and bags. The insulation helps keep liquids cool while out in the heat, and to keep them from freezing in the cold.
Bladder is not included. These carriers are aftermarket and not Military issue.