Suitable for computer, television, tape recorders, CD players, MP3, decks and amplifiers, speakers, etc. to connect and transmit their audio signals. Connect one end of the 3.5mm plug of the extension cord to the TV, the audio source socket of the computer, CD player, MP3, deck, and the other end to the stereo or earphone. When the extension cord is made, the 3.5-mm socket, that is, the audio signal output port, is connected to the amplifier of the power amplifier, and the other-end socket is connected to the plug.