C1 Multifunctional Car Dual USB Charger MP3 Music Player Bluetooth FM Transmitter 1. Simple operation, one key to hang up the phone, rotate the button to adjust the volume and frequency. 2. Bluetooth 5.0 high-speed connection, transfer audio and high-quality music from the mobile phone to the car stereo through FM. 3. After power on, the LED light will light up soft blue, which is convenient to find the USB charging port at night. 4. Built-in intelligent identification chip, intelligently match the current required by the device, and charge safely and quickly. Short circuit, over voltage, over current, over temperature, anti-interference protection chip. 5. Dual USB ports can be charged at the same time, with QC3.0 fast charging technology, fast charging will not damage the phone. 6. Efficiently compatible with all kinds of mobile phones, tablets, earphones, MP3, GPS navigation terminal electronic products, 2 can be charged at the same time. 7. Parameters: Bluetooth version: V5.0 Bluetooth transmission distance: 10-15m Frequency response: 20Hz-15Khz Audio format: MP3WMA Signal to noise ratio: 68dB FM transmitting frequency: 87.5-108.0Mhz Input: 5V~2A, 9V~1.8A Rated working voltage: 12-24V Power consumption: 0.5W Working temperature: -10~70 degrees Celsius Working humidity: 0~-0% USB charging output: 5V3.1A