ADCO 32827 Designer Series Tan/White Tyvek Class-A RV Cover Class A Designer series contour fit 3 layer RV cover; Fits 37'1" to 40' Great cover for regions with high moisture and extreme sun; Best cover for long term storage; Superior UV protection Tyvek Roof Panels extend down sides to cover awnings; side panels increase from one layer to three layers Strap and Buckles include a weight for easy installation underneath the coach Front and rear cinching straps and buckles