Technical Pro HB3502URIBT Digital Hybrid Amplifier with AM/FM Tuner, 3500 Watts, Bluetooth Compatible 3500 watts peak power Inputs - RCA (2 audio sources), USB, SD Card, MP3 Outputs - Banana binding post (4 speakers), push button (surround sound speakers), RCA (record line, preamp, 2 mono to subwoofer)USB & SD Card maximum size - 32GB Plays. mp3,. wav,. wma files from USB drives and SD Cards iPod compatible USB input allows for direct connection with an iPod