It's a Great 5.1 Surround Sound Digital Audio And Video System, Bring You a Amazing Watching And Listening. A Perfect 5.1ch Decoder For Movies, Games, Music. Including 2 Pcs Remote Controller. 5 Sorts Of Signal Source Input ( HDMI / Coxial / Optical / PC-USB / U Disk-USB / BT-5.0 ). You Can Switch The Signal Sources And Adjust Volume Freely, Through The Buttons On The Unit, Or Its Remote. (Note: When Audio Is Decoding To Output From The Decoder, You Can Adjust The Volume Only With The Remote Control Or Volume Adjustment Knob Of This Unit, And Can't Control The Volume Through Your TV Remote Control.)