The new Slide Seal feature opens the entire top end of the reservoir allowing quick and easy filling, turning the reservoir completely inside out makes it one of the easiest to clean and maintain. The reservoir features a baffle system to maintain a flatter shape, conforming to the shape of your back and reducing water sloshing. It also features a self-sealing Plug-n-Play connector for the drinking hose for quick and easy detachment. The reservoir is FDA approved, PVC and BPA Free.