Like a glove. This precision-made sleeve ensures a perfect, foolproof fit for your thru-the wall air conditioner. Designed to fit all standard 24-inch units, this thru-the-wall air conditioner sleeve acts like a weather-proof seal to minimize heat loss and protect the unit from the elements. It also acts as a noise buffer, reducing noise transmissions from the great outdoors into the great room—or any room. Constructed of galvanized steel with a durable painted finish, you can bet this quality-made sleeve is in it for the long haul.