ADCO 34857 Designer Series Gray/White 37' 1" - 40' DuPont Tyvek Fifth Wheel Trailer Cover Slip-Seam strapping system cinches at the top and bottom for a perfectly snug fit and prevents cover from wind damage; Reinforcements throughout bottom and top of side panels Water resistant but breathable; Tyvek RV top panel reflects sunlight, keeping RV cooler; Designer polypropylene sides Weighted buckle toss under for easy installation underneath the coach; Lapper cap reduces wear over ladder area Durable polypropylene grey side walls, 3 year warranty, 4 travel tire guards included with every cover The most durable All Climate 5th Wheel Trailer cover on the market; Fits 37'1" - 40'