Bluetooth hands-free call2: echo cancellation and noise processing during the call;3: Stereo Bluetooth and FM emission technology;4: Support USB/TF card/Bluetooth function;5: Support MP3/WMA format music;6: Automatic power off memory function;7: power: DC12V-24V voltage power supply;8: Bluetooth version 5.0 FM transmitting frequency: 87.5 ~108Mhz9. Auto voltage detection10. Panel shell with colorful atmosphere light display11:USB charging 3.1A/PD port charging 18W How to use car MP3: 1. Turn on your car radio and tune it to an idle frequency. 2. Insert the product into the jack of the car, and set the frequency of the product to be consistent with that of the radio just now 3. Insert the memory card or U disk that downloaded good songs into the device, or search the bluetooth configuration of the product through mobile phone Bluetooth 4. So the machine can automatically play music from the memory card or USB flash drive or the phone Note:1. It may connect to the last paired device automatically when turned on next time.(Turn on the Bluetooth of your smart device first, and then turn on the product2. For the best audio quality, please turn the volume of your smart device and FM transmitter into the max3. The signal of any FM transmitter sometimes can be interfered by the surrounded radio or the similar frequency signal thus cause noise, this is normal. 4. If the noise is too loud, please try another blank FM station Kindly place your order before it goes out of stock soon, thanks for buying the product.