Large Capacity Cross-border Multi-function Expansion Waterproof Charging Portable BackpackProduct information: Lining texture: Polyester Color: black, dark gray Processing Method: soft surface Outer bag type: Sandwich pocket Accessory type: shoulder padded backpack Material: Oxford cloth Popular elements: sewing thread Number of shoulder straps: double connector Lifting parts: soft handle Applicable gender: neutral both men and women Applicable occasions for gifts: travel commemoration Function: breathable, waterproof, wear resistant, anti