Material:The Backpack Is Made Of Polyester, Which Is Waterproof To A Certain Extent And Keeps The Interior Dry. Design: The Shoulder Straps Of The Backpack Are Very Soft And Strong, So That Boys Or Girls Will Not Suffer Shoulder Pain Due To The Weight Of The Backpack During The School/Trip/Picnic. Super Capacity: The Interior Of The Backpack Is Very Spacious, Can Hold A Lot Of Stationery Books, Laptop, Clothing.Backpacks On Both Sides Can Hold Water Cups And Folding Umbrellas, Which Is Very Practical. Backpack: Purchasing Notes: 1-2cm Error Of Measuring Is A Reasonable Range Due To Different Measurement Methods. Each Backpack Will Be Check Carefully Before Shipped, But It'S Still Very Hard To Make Sure There'S No Extra Thread. The Actual Color Of The Backpack Maybe Different From The Picture Shown Due To Lighting Effects, Monitor'S Brightness / Contrast Settings When Shooting.