Our backpacks have a concealed waterproof rain shell at the bottom, which you can pull out to cover your backpack, just like a large backpacker's backpack. We recommend reapplying waterproofing spray every so often just to be sure.If your bag ever gets wet for some reason, please do not dry it in a dryer as this would shrink it. Simply remove the contents; detach the rain shell and hang the bag to air dry.