The Budge Standard class B RV Cover has a top panel that is made from a 3 layer water resistant spunbond polypropylene. This cover features single layer side panels that are durable and lightweight, providing reliable protection to your RV. Full height zippered panels are included so you can access your RV while covered. This cover has a reinforced roof for extra durability. The Standard RV cover will protect against sun, dirt, occasion rain and heavy dust. This cover is fully breathable and UV treated.