Nexify 3L Hydration Water Bladder Outdoor Backpack Cycling Bag Hiking Climbing Pouch + Bike Chainstay Protector ALL DAY HYDRATION - Each bladder holds up to 3 liters of water to help you maintain healthy hydration even in the most intense heat. DUAL LAYER DESIGN - Made of waterproof, high-density nylon, each backpack features a cargo slot for a hydration bladder and one for carrying extra items. ADJUSTABLE FIT - Along with the easy-to-fill bladder top, the hydration bag features adjustable shoulder straps and a chest belt for a comfortable fit. LEAK PROOF - The precision threated screw on bladder top and long, accessible drink tube keep water from leaking on clothes or being wasted. ON/OFF BITE VALVE - Control the proper amount of water per drink with that convenient flow control bite valve that lets you sip or gulp depending on need.