BLUETOOTH FM TRANSMITTER EASY TO USE: Plug Bluetooth FM Transmitter into the car cigarette lighter; Tune the car radio into an unused FM frequency(range from 87.5 to 108 MHz), then match this FM Transmitter to the same frequency; Pair this handsfree car kits with your phone/ tablet via Bluetooth. Then you can listen your favorite songs or make phone calls. If there has an incoming call, this unit will automatically switch to telephone when you are in music playing mode.DUAL USB CAR CHARGER: Wireless Audio Cell Phonoe hands free car transmitter has 2 USB charging ports, One is designed with QC 3.0 Quick Charge which quickly charges your device to 50% in only 30 minutes; the other is designed with 5V/2.4A with music symbol which can both charge your device and read USB disk to play music. Built-in over-current protection, over-voltage protection, intelligent temperature control, short circuit protection, it will effectively ensure safe charging.FM TRANSMITTER HAVE WIDE COMPATIBILITY: Bluetooth Car FM Transmitter is compatible with most Bluetooth enabled devices, and all vehicle type including car, van and truck(12-24V). Stream music and make phone calls directly from your cell mobile devices to car stereo system speaker via FM radio signal( 87.5-108.0MHz).FM TRANSMITTER HAVE HANDS-FREE CALLING: This FM Transmitter Adapter comes with bulit-in Microphone and Noise Suppression (CVC) technology, hang up, reject incoming calls or redial the last number with a click of the button. You can use the multi-function buttons to control calls and music, seamlessly switch between calls and music, for safer drive. In addition, it also supports voice navigation for mobile phones.