1. Enjoy hands- calling: Provides a stable connection, echo cancellation can reduce background noise, and achieve better hands- calling, so you only need to press the button to answer calls. 2. [Dual USB Ports]: Enjoy simultaneous high-speed charging for driver and passenger or plug a USB drive into the top port to play saved files through your car's sound system. 3. Intelligent charging: Charging speed is 4 times faster than standard chargers, and compatible devices can be charged to 80% in 35 minutes. The Bluetooth FM transmitter can charge two devices simultaneously. 4. [ More audio playback modes ] Bluetooth connects to your car radio through FM channels, and then you can play music to the car stereo from your Bluetooth device/USB. Built in overcurrent/overheat/short circuit/overvoltage/high temperature protection devices ensure stable current output.