Dolby Pro-Logic Decoder with built in amps for center and surround channels. Obviously meant as an add-on for an existing 2 channel system. Brand new, but box is open. Well built, quality piece. Includes remote/instructions. I won this on another HT forum, and have no place to use it in my system. MSRP, $549. Looking to get $175. Buyer pays shipping. Will consider trades for tactile transducers,or a minidisc recorder, or a 2 channel amp with more current than my Sony STR-DE935 receiver. Make me an offer!