Stormpro™ Pontoon Boat Cover 20 feet has an integrated buckle and strap system for easy fitting and trailering-adjustable straps snap into quick-release buckles on the cover. Storage bag and trailering straps, transom flap tie-down rope and two stern-fit elastic cords included. Adjustable elastic hem cord sewn intoentire bottom hem provides a tight, custom fit. Dual air vents reduce inside moisture and ballooning of cover at high speeds. Adjustable transom-flap for a superb fit. High strength polyester StormPro™ 600D Marine Canvas designed for extra durability and all-weather protection. Fabric coating technology and heavy-duty fabric for maximum water resistance and repellency. Resistant to mildew and UV damage. Won't shrink or stretch. Fits most popular pontoon boat with three sizes. 5 year manufactureres warranty.