Bose Virtually Invisible 191 speakers (Pair) Proprietary ported enclosure produces cleaner and deeper low-frequency performance mainly directed into the intended listening area, not into adjoining rooms Proprietary enclosure technology ensures consistent performance regardless of space behind wall or above ceiling Includes both rectangular and round grille frames and grilles.White grilles are paintable for a custom look Use as in-wall surround sound speakers with your home theater components or your stereo system This item is Non-Returnable