Proster Bluetooth FM Transmitter LCD Wireless Radio Adapter Handsfree USB Car Kit MP3 Player for iPhone SE 6s 6s Plus iPhone 7 7Plus Samsung Galaxy HTC iPad During the bluetooth connecting ,play the phone's music and FM transmitter to Car Audio, perfect ,as calling incoming automatically switches to the speaker's state, call end then automatically back the music player. Bluetooth Answer, Hang Up, Reject, Redial Calls and Other Functions not only support Bluetooth Handsfree call but also music play. With aux input port, TF card slot and USB ports, supports U disk TF card player; Supports mp3, WMA, FLAC format music LCD digtal display; Full frequency FM transmitter. Suports Voltage detection, Voice navigation Supports USB output voltage, the maximum output 5V/2.5A