UIW RSS III In-Ceiling/In-Wall Bipolar Loudspeaker. Reference In-Wall/In-Ceiling Surround. Specially designed for use in custom home theaters of the highest quality, UIW RSS III speakers deliver spacious surround sound while remaining practically invisible in your wall or ceiling. Featuring two aluminum dome tweeters, a pair of 3.5” cast-basket drivers and two 3.5” pressure-coupled Low Bass Radiators, the UIW RSS III produces a uniquely immersive experience that completely envelops listeners in an expansive, 360-degree soundstage.