I was attracted to the small size and light weight of this device. I have an older Plantronics 510, and the old 510 is way better than this new 665. The quality of sound of the 665 is so bad that I am returning it for a refund. Everyone that I have ever called on this thing complains that it picks up every little sound around me. If I try to call someone while driving, the noise from my quiet little car is so loud that nobody can understand what I am saying. My wife won't even talk to me if I call her using it. I am just going to keep my old 510.