High-quality audio performance, with clear sound at any volume. Use the auxiliary input to bring Bose performance to another audio source such as your iPhone or iPad. Upgrade your sound-and your experience-with Bose Companion 2 Series III speakers.High-quality audio performance, with clear sound at any volumePlay an additional device-just connect to the auxiliary inputVolume control/headphone jack on front of right speakerOperating compatibility: Mac, Windows XP