beFree Sound 5.1 Channel Bluetooth Surround Sound Speaker System 5.25" Amplifier + 5 3" Speakers- Bluetooth 1 SDMMC Card Slot 1 USB Port, FM Radio Output Power: 50W+18W*5, Frequency Response: 40Hz-20KHz Separation: 50dB, S/N Ratio:75dB, USB, SD Compatible Remote Control Included (Remote requires 2 AAA batteries, not included)