Classic Accessories 80-030-171001-00 PolyX 300 Grey Travel Trailer Cover Air vent reduces wind lofting and inside moisture Special compression stuff sack system reduces bulk for easy storage Offers access to the travel trailers door and the extra long zipper pulls help reduce the need for a ladder Integrated strap attachment and weighted toss bag system eliminates crawling under the travel trailer to install attachment straps Easy installation, custom fitting and extra strength for the life of the travel trailer