Bell'O Digital BDSW-1650-BLK 6.5-inch Wireless Subwoofer, Black Works with BellO Digital Sound Bar Shelf, sold separately, along with select BellO Home Theater Furniture and ClassicFlame electric fireplaces with integrated speakers Single 6.5-inch bass driver with built-in high-current 40-watt amplifier for thundering bass sound Energy efficient speaker system produces thundering bass with low wattage consumption Simple and hassle free set-up - just plug in the wireless adapter to select Bell'O Digital wireless enabled sound systems and select pair Adjustable volume control allow you to set the proper volume for your listening experience