S21 speaker comes with a powerful bass giving a superior listening experience for everyone. The S21 is ultra portable and has a stylish design with LED lights that will bring set the tone for your party. Power input is DC 5V via a USB port along while the audio output is through a 3.5mm audio jack which can be connected to a desktop PC, Laptop or a smartphone too. 2 speaker units with 2.5W RMS each provide a powerful output total of 5W RMS