The Altec Lansing BackBeat 903 are wireless stereo headphones with built in microphone making them ideal for stereo music and cell phone use. The wireless design allows them to be used as you walk, run, work or play without the annoyance of a cable getting in your way. The AudioQ dual-mic technology not only allows you to use this headset with a cellphone, but it also can seperate your voice from surrounding noise for exceptional call clarity. The OpenMic button also lets you hear the world around you without having to remove the headset and the bass-boost feature will allow you to enjoy the full dynamic range of your music. The telescoping and swivel adjustments help you find a perfect personal fit, and the flexible desing allows them to be easily stored in your pocket or bag. The Altec Lansing BackBeat 903 is also sold as the Altec Lansing BackBeat 906, which includes a Bluetooth adapter for use with non-Bluetooth devices.