The CK3100 bluetooth hands free kit is the most popular one requested to date as it is easy to operate. The display allows you to identify who is calling and enables you to search through the menus just as if you were using your mobile phone. It can be integrated through your car stereo which will mute the music when in use. The display is mounted within a hands reach so you can easily answer or make a call. Your phone remains in your pocket or hand bag. This kit does not charge your phone when in use.