[Fast Charging]: The Bluetooth car adapter has 2 fast charging ports (PD18W and QC3.0) and 1 5V/1A charging port. Compatible with all versions of fast charging technology (1.0, 2.0, 3.0), providing the fastest charging speed. It is suitable for all USB devices, and there will be no problem with charging the charger incorrectly or charging multiple devices slowly. [Siri/Google Assistant and Hands-free Calling]: Connect the call hands-free via mobile phone and Bluetooth. Supports Siri and Google Assistant. When driving, press and hold the multi-function button for 3 seconds to start siri to operate the smart phone and make a clear call via the built-in microphone. Use a hands-free design to keep your conversation safe while driving. [Aux In/Out] The Aux In/Out port turns the FM transmitter into a Bluetooth auto audio receiver. It means that when your car has no radio or the radio is broken, you can connect the FM transmitter to the car via the supplied Aux cable. In addition, the connection with the car via the auxiliary line is more stable and of high quality. [Bluetooth V5.0, lossless sound quality]: Using Bluetooth V5.0, the connection of the car Bluetooth transmitter is more stable, faster and does not drop. The built-in DSP cancellation technology can reduce the noise of the external environment very well, and the music sound is more pure and clear. We hope to bring you unlimited music enjoyment. [Rotation and memory function] The Bluetooth FM transmitter can be rotated 60 degrees up and down and about 120 playbacks, which makes it easy to play. using the hands-free port and the charger. Power-off memory playback: It will automatically reconnect after power-on, and the song will restart from the power-off time and play from the beginning. Product Adjust the FM frequency of the transmitter: Press the "CH" button of the transmitter to enter the "FM" mode, the LED flashes, turn the multi-function knob left/right or press "Next/Previous" button to adjust FM 87.5~108MHz. No operation within 3 seconds will automatically exit the state. To pair the FM transmitter with the car radio: Insert the Bluetooth FM transmitter into the cigarette lighter socket from the car, tune the car audio FM to a blank station, then tune the transmitter FM to the same blank station. 4 music playing modes BT/USB/TF/AUX music input mode switch: Press "M" key to switch input mode. After inserting TF card/U disk or selected music from mobile phone/MP3, the device will automatically play the music. Bluetooth V5.0 provides you stable connection and fast pairing. Supports A2DP charging and external microphone with noise reduction technology. Dual-screen display The unique dual-screen display design allows you to view more information in a more intuitive. It can display FM frequency and car battery voltage, which is very convenient for reading day and night. U disk/TF card Insert the TF card/the U disk or select the mobile phone/MP3 music, the radio frequency and the Bluetooth frequency are set to the same to play the U disk songs, the device will automatically play the music. Google Voice Assistant and Hands-Free You can use Siri or Google Assistant to make calls, send texts or get directions, so you can focus on the road. You don't have to look at your phone often anymore.