To reiterate: This headset is for the Treo 650 only. That said, the reviewer was impressed with the range, sound quality and comfort of this ultralight, over-ear headset. In addition to volume controls on the side and a series of bright LED's for advertising the mode the headset is in, the 650 Headset sports a multi-function button on its face. With this single button, one can Answer, Mute, Redial last number, Reject an incoming call, put a call on hold and use call waiting, not to mention powering the unit off. The unit even comes with a charger that will also charge your Treo, saving even more space in your carryon luggage. With any wearable device, try it before you buy it to make sure it will fit and be comfortable for normal use. Otherwise, this is a killer hardware app for the Treo 650.