FM Transmitter Car MP3 Player TF Card U Disk Playback 3.1A USB Car Charger Handsfree Bluetooth 5.0 Car Kit FM Modulator - Name:Dual usb car FM transmitter - Material:Aluminum Alloy + ABS - USB ports:Dual USB Charger 3.1A & 1A - Working Voltage:12-24V - Wireless Version:5.0 - Support type:MP3 / WMA - Capacity:TF Card U disk<= 32 G - BT sound processing: A2DP (Advanced Audio Distribution Mode) - FM frequency: 87.5-108.0MHZ Package include: - 1x car fm transmitter - 1x user manual - Pay Attention : In order to save on postage costs, the items are not packed in boxes, only simple bags. How to use MP3 in the car:1. Turn on the radio in your car and tune it to an idle frequency (i.e. a frequency with no local broadcast) 2. Plug the product into the car cigarette lighter socket and set the frequency of the product to the same frequency as the radio just now 3. Insert the memory card or U disk with downloaded songs into the unit, or search the Bluetooth configuration of the product by Bluetooth on your mobile phone Question and Answer Question 1: What is the FM transmitter? Answer: FM transmitter is a very small FM Radio Transmit Station with a broadcast range of <5 meters. Main function: Transmit the audio to your car FM radio via the same FM bands, Then you can hear this audio in the car speaker. Question 2: Why my car FM Transmitter function is so noisy? Answer: FM Transmitter transmits the FM band in 5 meters. We know the FM radio station is a very wide range, if we set the same band with radio, our signal will affect a lot. So we can follow the steps as below, 1. We adjust our car FM to the band without the radio station, like 108.0MHz. 2. We change our device FM band to the same band with car FM -108.0MHz. 3. We can play music via TF card or Bluetooth, check the quality of sound. Question 3: When playing music, get an incoming call, why the sound volume becomes louder or lower after answering it? Answer: Because the calling volume is controlled by the " Calls " and music volume is controlled by " Media " in your phone volume settings. So you can modify the settings on your phone to let the sound more comfortable.