【Material】 Nylon Water-Repellent Fabric: Nylon Taffeta (Thin) 【Size】 Size: Free. Fits large backpacks that accommodate A4 files. 【Features】 Comes with a convenient storage pouch. An elastic band goes all the way around, so it easily fits over the backpack. Easy for even young children to put on and take off. Prevents rain and snow from entering from the sides, protecting important textbooks from getting wet. Comes with a storage pouch to put the cover in when wet. Can be hung on the backpack hook when not in use. A single point mark makes it easy to tell which way is up. 【Caution】 Although it is a water-repellent fabric, it is not completely waterproof. If the water-repellent effect diminishes, please use it in conjunction with a waterproof spray, etc.