The Altec Lansing T515 is a wireless Bluetooth speaker system featuring a central speaker unit and a detachable/rechargeable Bluetooth handset. The headset can receive wireless signals from a Bluetooth-compatible cell-phone or computer via A2DP technology, and then play it through the system’s powerful speakers. Or the user can detach the headset, clip it onto their shirt, and use the included stereo earbuds to receive signals instead. What really distinguishes this unit, however, is that the headset features a microphone, allowing users to receive phone calls. Basically, the Altec Lansing T515 functions as a speakerphone (cell phone to handset to speaker), a Bluetooth handset (cell phone to handset to earbuds), and as a music player. Included also is an auxiliary input on the speaker system for attaching an MP3/CD player or iPod.