?Automatic Tuning for Unused Station?The FM Transmitter adopts an upgraded chip with just a simple tap of the pressing ' CH/A' button twice, and it could automatically search for the unused radio station. It connects to your car when you tune the car radio to the same FM station as the FM Transmitter shows. | ?Two Microphones for Voice Recognition?This Upgraded Bluetooth Car Adapter with two microphones to pick up of voice in two ways and noise suppression (CVC) technology ensure nothing interrupts your calls by filtering out road and wind noise. Also, it supports active Siri or Google Assistant to make phone calls, phone GPS and send texts while driving, etc. | ? Quick Charge for Two Devices?One USB port is quick to charge 3.0 port (up to 5X faster than standard chargers), which can charge compatible devices to 80 percent in just 35 minutes. The other USB charging port is optimized to support 5V/1.5A for charging faster and reading U disk for playing music, meet your need to charge your phone and listen to music at the same time by using this FM Transmitter Bluetooth for Car. | ?Big Knob Button for Volume & S.T?With super wonderful ring knob button, you can easily turn the knob button to tune the volume up when the volume is low for you, also it could change FM station, compare with other Bluetooth FM Transmitter for Car in the market, more quickly and accurately. Also, all the buttons are on the same side and are easy to control compatible with a 12-24V car cigarette lighter. | ?Stereo Music & 9 Colors LED for Ease Driving?This FM Transmitter Car Radio provides 2 music playing modes: Bluetooth mode/ USB flash driver (=64G) with its clear and stereo sound. Also, it has 9 adjustment modes (1Dynamic/Static RGB/7 Monochromatic Light), which can be used to illuminate the transmitter and match different music, making your journey no longer lonely even in the dark and cold night (Note: The light can be turned off). | Connector type: USB 3.0