The topeak trunk bag rain cover has been designed to protect your topeak trunk bag when the weather gets bad the trunk bag cover comes in four different sizes to make sure you get the perfect fit for your rear rack bag with 10 off when you order online there is no reason for your pannier bag to get damp again choose from the drop down box to ensure you get the correct fit for your bag and if you need help feel free to give our friendly sales team a call on 0800 083 0888