Specification: 1. Power supply: Batteries(AAA 1.5V*4),DC5.0V(USB cable for PC),or AC power Adapter cord(output 6V,350mA) 2. Output power: 1.0W*2 3. Frequency response: 20-20KHZ 4. Impedance: 4R 5. Unit Speaker : 50mm*2 6. Signal to noise ratio: >>75db 7. ENV-friendly stuff: ABS plastic 8. Plug: Stereo 3.5mm