I have had this unit for a while, since new. Had this when 5 or 7 channel recievers were just getting started. SO... some of you may have 2 channel stereo systems and may want to add center and rear surrounds to your system, well this will do it for you !! This unit adds those 3 channels, has an amp in it to power those channels. 2 programs for Dolby Surround, AND adds 4 programs of sound field processing, 3 center channel modes. Test tone generator for speaker balance adjustments. Comes with manual, remote and orig. box. Buyer pays shipping from Oregon. Paypal add 4%. Sounds GREAT, Yamaha's Natural Sound.