Product Description: Bluetooth vision:V3.0 Bluetooth protocol:A2DP, AVRCP, HFP Bluetooth band:2.4 GHz-2.48 GHz unauthorized ISM band Bluetooth Transmission distance:5meters FM frequency:87.5-108 mhz FM transfer distance:2meters Input voltage:12-24V Output:5V/2.1A Music format:mp3, wma Features: 1. New Wireless Vehicle Bluetooth FM Transmitter Car Charger. 2. Automatically adjusts the voltage received from the vehicle so your device always charges at a constant rate . 3. Multifunctional: Wireless connection(Bluetooth), Build in microphone, FM transmitter+USB Charger+MP3 Player. 4. Adopt CVC technology for controlling the noise and winds, help to stable the music's quality. 5. The main button on the middle supports to change music or swap call, the near rotary knob is designed to adjust the volume. Package content: 1* Wireless Bluetooth FM Transmitter (the TF card is NOT included) 1* 3.5mm Audio cable 1* User manual Note: The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness. New Wireless Vehicle Bluetooth FM Transmitter Car Charger Automatically adjusts the voltage received from the vehicle for consistent charging Multifunctional design: Wireless Bluetooth connection, built-in microphone, FM transmitter, USB charger, and MP3 player Adopts CVC technology to reduce noise and wind interference, enhancing music quality Main button allows for easy music control and call swapping; rotary knob for volume adjustment