PremierAcCovers Heavy Duty Window Air Conditioner Cover - Window/thru Wall - 2PC SET Outdoor/Indoor 21W, 15H, 15D 21W, 15H, 4D - GRAY Customer feedbacks agree .. this is the answer for Winter protection. All our covers are made in the U.S.A Full 2 year manufacturer's warranty. PremierAcCovers - Our covers are made of heavy duty material saving on your heat bill.