The METRO.fi 150V features intergated voice functionality and is specifically designed for use with the iPhone (and other mobile music phones with the same headset jack). A miniature high preformance microfone allows for hands-free phone calls. An in-line multi-funcion button answers the end calls and controls music /video on your iPhone. The METRO.fi 150 has excellent acoustic speaker technology, making it the best single value in-ear speaker product on the market. The METRO.fi 150 is a very comfortable in-ear design and provides noise isolation that reduces ambient interference and enhances quality of sound.