Dual structure: Our waterproof backpack rain cover is made of 190T nylon. The feature of the tear-resistant outer fabric protects the backpack from scratches, dirt and sand. The waterproof material keeps the inside of the bag dry. Super waterproof roof: The silver PU inner coating provides rain resistance up to 1350 mm, which is very suitable for all rain and snow activities. Upgraded buckle straps: This rucksack rain cover is equipped with adjustable straps to increase stability and secure the rucksack cover in place without slipping off. Wide range of uses: Due to the foldable function of this backpack rain cover, it can be used as a computer screen protector, seat cushion, bicycle rain pad, electric fan cover and any equipment that must be waterproof in rainy days. Easy to use and store: This backpack cover is easy to put on and take off. Each backpack cover is also equipped with a carrying bag with carabiner. When folded into the carrying bag, the rain cover is small and light, and does not take up too much space. Product description Brand is your best choice. The rain cover is very suitable for hiking, camping, traveling, biking, hunting, and mountaineering. Protect your backpack from dust, scratches, rain and snow. Suitable for hiking backpacks, travel backpacks, camping bags, camera bags, the inner frame is less than 80 liters. It is also very suitable for college backpacks to keep your laptop and books dry and clean. There are 5 sizes to choose from (suitable for backpacks from 15 to 75 liters). Size chart: S: 15 to 25 L (height: 34 to 45 cm, length: 28 to 32 cm, width: 15 to 17.8 cm). M: 30 to 40 L (height: 45 to 52 cm, length: 32 to 37 cm, width: 15 to 18 cm). L: 40-50L (height: 52-60cm, length: 32-37cm, width: 18-22cm). XL: 50-65 L (height: 60-70 cm, length: 32-37 cm, width: 22-25 cm). XXL: 65-75 L (height: 69.8-74.9cm, length: 36.8-41.9cm, width: 24.9-27.9cm). (If you plan to store things outside the bag, we recommend that you take one size larger from the bag)