3L Hydration Bladder: Detachable water reservoir with expanded filling opening included. Made of food grade EVA materials. Its wide opening makes it easy to clean and add ice cubes. The ON/OFF valve helps to adjust water flow and prevent leaks. 2 Functional Compartments: The main pocket contains a 3L/106oz water bladder with a large opening and a smaller one which connects the smart tube. The back layer for storing personal belongings like cellphone, wallet, keys and so on. Comfortable Design: Two adjustable shoulder straps and a secure strap keep the camel bag on your back and reduce bounce, making it perfectly fit your shoulders, chest and waist. Suitable for men and women. Good Quality Material: This running water backpack weighs only 0.8lb. Made of 900D high-density Oxford fabric, lightweight and wear resistance. The soft back section will keep your back comfortable and breathable while you hold it during outdoor activities. Versatility: Outplea tactical hydration backpack with water bladder will be a great partner for hiking, cycling, running,climbing, hunting and any short trip.