1.mini portable speaker 2.classical design, superior performance 3.with belt, easy to carry Functional Description: 1, built-in ... .7, built-in lithium battery, MICRO USB interface charging.8,3.5 stereo audio input interface, easily connected to the notebook ... inches 4 ohmsOutput power: 3WFrequency response: 90-20KHzSensitivity: 80dBDistortion: <0.3%SNR:> 80dB