Proficient Audio Systems - AIRFLEX RECEIVER AirFlex is the easy way to set up a multiroom wireless audio Use it to distribute sound to multiple rooms or use it to connect surround speakers or subwoofers The receiver has speaker outputs, a full-range mono subwoofer output, a 3.5mm line in jack, a volume knob and a remote control Must be used with AirFkex Transmitter. (Not Included)