AYAMAYA 30L-65L Waterproof Backpack Rain Cover Rucksack Water Resist Cover for Hiking Camping Traveling Capacity: 30L-40L are available Specially reinforced, keep your backpack and belongings dry from rain, mud and dust. Made of waterproof wear-resisting Nylon material, durable, portable and useful With elastic design, it is able to adjust the size according to different backpacks. Perfect for outdoor travel, riding, climbing, hiking and so on