Specially designed for Class B RV's. Triple-ply PolyPro III fabric top keeps out rain and snow. Built-in air vents reduce wind stress and help reduce moisture and condensation between the cover and RV. All-season protection against the elements, UV, nicks and scratches. Integrated tension panel/webbing attachment system. Adjustable rear tension panels. Elasticized hem corners provide a custom fit. Zippered access panels to RV doors and engine area. Toss bag help reduce crawling beneath the RV. Stuff sack included.