Leader Accessories Class A RV Cover Fits 40'-42' 3 Layer SFS Size 515"x106"x120" Fits 40'-42',Size: 515"L X 106"W X 120"H 3 layer polypropylene top fabric keeps out rain and snow while single layer polypropylene side fabric venting inside vapor out Anti-hit reflective panels for added safety at night or while parking Air vents reduce wind stress and vent inside moisture out Extra reinforced corners with elasticized hem for custom-like fit and prevent tearing of your cover