Bose Quality Audio. Subwoofer is the Power Supply for the Unit and has a Dial for the Intensity of the Subwoofer.

The Surround Speakers are 2" Speakers x 2 Speakers x 2 Speakers per Speaker. 

The Control Dial has Audio Input/Output as well as the USB Connection for the Speaker Base . 

The Control Dial is the Power On/Off also. 

Nice Speaker Set, the Speaker Sound from the Bose Companion 5 is slightly Improved over Previous Bose Media Systems, due to the Extra Speakers. The Connection being USB rather than AUX 3.5 is not as convenient however easily Connect to the Volume Control using any 3.5 Audio Connection. The Device itself is Nice, the Subwoofer is Heavier and about 3-5 Longer in Length than the 3 Series Media Speaker System. Great Audio System. With the Alexa Device (Connect Via Audio Volume Control) the Device is a Home Theater System, a Speaker System, a Audio System, an Internet Radio, Spotify, Pandora, Amazon Music, etc...