Amazon.com : G4Free 50L Hiking Backpack Waterproof Daypack 。Material: Nylon ✖ Polyester and water repellent processing, it is resistant to dirt and durability. Size: 27 cm × Side 14cm × 33 cm. Large capacity design, square type + wide. You can carry the necessary items such as laptop, A4 magazine, lecture material, iPad, and water bottle. Features: convenient to store the contents of the bag and back and forth, convenient pocket, convenient to store items such as wallet, notebook, and iPad, and small items that can be lost easily. Design: stylish, des