- Switch MP3 stereo hands-free to cell phone hands-free, you can enjoy MP3 stereo music as well as use MP3 hands-free as a cell phone handsfree
- With Micphone, add speak function to MP3 stereo hands-free
- Switch button, switch from music audio both ears to Mono single ear
- Mute switch, shut down micphone for listening function only
- Volume control, control volume online when switch between MP3 and cellphone


















