This is a Geek Squad Certified Open Box Product. See below for more information. Experience immersive sound with the Sonos Sub 4 wireless subwoofer. Featuring dual force-cancelling woofers, this device delivers pulse-pounding bass. Pair it with Sonos Arc Ultra, Arc, or Beam for deeper audio in movies and games. Enjoy rich music clarity by pairing with Sonos Five, Era 300, or Era 100. Trueplay optimizes the audio according to the room acoustics.