TOFINE Heavy Duty Hidden Pocket Outdoor Water Proof Travel Backpack Green 25L nylon Imported Backpack Material: water resistant nylon, self-repair zippers, better ventilation not easy to deformation, Super versatile and multi-functional pack. Capacity: 25 L Keep hydrated, store your books, and put your 13 inch laptop in the sleeve all in a compact backpack With Rain Cover can protect your stuff from the rain, have big room for a Hydration BLADDER, your iPad, mobile phone, A4 documents, books, magazines and other accessories Main compartment is large and flexible to handle many items Padded back panels with mesh for ultimate comfort