Audio earphone adapter fits for use with guitar amps, stereo system, headphones, etc. When use must first insert the headset and microphone on the transfer line, and then put on the mobile phone's headphone jack tieline can be normal use. Compact design for maximum portability, lightweight, yet sturdy design that can easily be plugged in when required. Handy connection: headphone jack enables you to connect your headphones or stereo other compatible devices.