Zipper closure It is a very popular multipurpose backpack, suitable for different people, suitable for various occasions, can be used to travel, trekking, hunting, hiking and other outdoor activities, for both men and women, It is a general daypack. But it have some Molle system, you can add different small pouch or Velcro on it, make the backpack different with other backpacks. This 3-day travel backpack has four main loading space, the front compartment can hold the cell phone wallet, the key and so on, the middle compartment can put the flat plate and the book, the main compartment can put some clothes and so on it works great to hold all of those just Incase items, like fuses and food, flashlight, anything Incase of an emergency. Plenty of room for a lot of stuff and plenty of separate compartments you have organized. Water bottle mesh pocket in the side(bottle not included).It is convenient for you to drink water in outdoor activities, MOLLE system in the front, you can add pouch, mountaineering hook can be used for hanging small things, the side of the buckle can make this large backpack more compact, more comfortable to carry, you can put some name card or flag in front of the Velcro, make this outdoor backpack more personalized There are two walkie-talkie pouch on the back strap of the bag , It is convenient to use walkie – talkie when you walk, adjustable chest belt can disperse the pressure of this military backpack, carrying more comfortable, and adjustable belt, let the whole tactical backpack fit our body, additional straps around the chest and waist to distribute the weight better. This is an expandable backpack, which can be expanded by zipper on the side. The thickness of the side can be switched between 8 ‘and 13’, and the maximum packet capacity can reach 64L. Can hold more things and the side buckles make it easy to secure it and reduce the size if it’s full, and this backpack is waterproof, very suitable for outdoor activities.