Maxi Pop-Top Caravan Protection Cover (18ft-20ft) Suits only pop-top caravans. The size is a large size (18ft-20ft) Don't be mislead by cheap imitation brands!! RRP $300.00 This superior cover has the following features: 420 denier polyester waterproof silver material with added U.V protection for longer life. Reinforced corners for maximum durability. Elastic stitched hem for universal fitment. Nylon securing straps and buckles. The 18ft - 20ft poptop caravan cover has 3 zippers to access your door. This 3 zipper model will allow you to be able to access your entry door whether your door is at the front or back of your caravan.