[Waterproof] The oxford inner lining and non-woven outer lining protect your window air conditioner from sun exposure and prevent dust, rain, or snow from damaging your window air conditioner in inclement weather. [Universal Size] The elastic bag mouth design is best for air conditioners up to 14.7” D x 21” W x 15.4” H in size. Before purchase, please check your air conditioner dimensions to ensure a tighter fit. [Double Straps] The two buckled straps can be adjusted for a tight, secure fit around your window AC to ensure the cover can protect your unit from the elements. Tighten the straps around your unit for superior protection even on windy, high-rise buildings so it doesn’t slip off. [Easy Install] Simply slip the elastic mouth over your unit and tighten the two adjustable buckle straps. It doesn’t get any easier than this! [Before First Use] When the product is opened there may be a “new product” smell. This is normal, but you may want to open the cover and place it in a well-ventilated place for a few minutes to get rid of the smell.