PremierAcCovers Air Conditioner Cover -Summer/All-Season Top Cover- 36X36 - GRAY This winter ac cover provides top protection during winter with its tight breathable mesh and does not cause rusting to your ac unit. This ac cover is NOT waterproof. We also sell Premier waterproof tops Highly resistant to sunlight, mold, mildew, and temperature extremes. All PremierAcCovers are made in the U.S.A with American made materials.