Thick triple-ply PolyPro III fabric top keeps out rain and snow while venting inside water vapor and condensation Cover protects against rain snow UV rays dirt nicks and scratches Integrated air vent system combined with a wicking PolyPro III top and quick-drying PolyPro sides reduce wind stress and vent inside moisture Zippered panels allow access to RV doors and engine areas Adjustable front and rear tension panels and elasticized hem corners provide a custom fit Integrated rope attachment system and a provided toss bag help reduce crawling under the RV Stuff sack and ladder cap included Three year warranty Fits 20 to 23 L Class C RVs