Stable Bluetooth transmission: Advanced Bluetooth 5.0 technology can provide stable connections for streaming music and hands-free calls through frequency modulation. Built in microphone, supporting smart voice navigation on mobile phones, one click answer or end call is very simple. No need to hold a mobile phone, making your driving safer. Fast charging: The car charger adapter can quickly charge two devices simultaneously through the PD24W C-port and 2.4A USB port.Built in overcurrent protection, overvoltage protection, overcharging protection, overload protection, and short circuit protection ensure safe charging of the charger adapter. Bluetooth hands-free call: one click answer/reject/hang up/call all functions. It can also automatically switch between incoming calls and music. After plugging in the power, display and detect the vehicle voltage. Enjoy voice control and safer driving with this Bluetooth FM transmitter. Fidelity sound quality and noise cancellation: Noise cancellation technology can reduce background noise, providing you with high-quality streaming stereo music and clear calls.