Works as advertised ... for a while. However, after a little use, and getting some sweat on them (these are sports headphones, right?), the volume buttons failed to work. Worse, the "down" button repeated itself, dropping the volume to minimum, and the "up" button wouldn't respond, so the headphones became uselessly stuck at very low volume. So I sent this first pair in to Motorola for an exchange. They responded admirably with a new pair. Amazingly, after a few more weeks of use, this new pair did the exact same thing! A bummer because I like the features and convenience.The only other negative is that for phone conversations, the sound only comes in one ear, not both.