Dohomai Bluetooth Fm Transmitter Wireless in-Car FM Transmitter Radio Adapter Car Kit Dual USB Car Charger iPhone 7 7plus 6s 6 Plus 5s 5 Android Cellphone Samsung iPod Mp3 Player Bluetooth handsfree function is available for the bluetooth fm transmitter,when cell phone bluetooth is matched with this In-Car fm transmitter,and then you can pick /hang up /redial calls Adjusting the car radio frequency same to the wireless fm transmitter,and connect your phone,you can play the music from mp3 or cellphone can be played through car audio system,you can enjoy high sound quality songs anywhere. There are 2 charging usb in this A2DP bluetooth fm transmitter,you can charge two cell phones in your car. A cigarette lighter hole is in the car bluetooth charger,you can put another car charger or similar devices in it. Independent ON/Off button is on the top,you can turn on or off the bluetooth car kit by pressing it,and needn't take the car bluetooth out of socket.