This Bluetooth MP3 player with car charger is designed for car. It uses professional high-performance Bluetooth module,with built-in MP3decoder chip that can transmit music files from micro SD card to car stereo via wireless transmission. When calls come in it can switch to hands free phone state,after end the call,it switch back to music playing mode.With the wireless transmission ,you can enjoy the music from your phone and answer the phone call safely when you driveFeatures1:Any angle adjustable, and applicable for all types of vehicles2Full Channel FM Transmitter 87.5-108. 0MHz3LED Display4AUX Line Out5: Car battery voltage/load current6Supports micro SD Card7Supports MP3 files8: Answer/hang up/reject/redial phone call9: Bluetooth stereo music play10: Call Echo Cancellation and Noise Reduction (CVC) technology11: Dual USB output , 5V/2.1A(Max) 12: Automatic memory function of power failure frequency point13: Supports charging agreement Description*Two USB, total output 5V / 2 .1A (maximum) *Charging intelligent recognition*micro SD card slot*CH /Next*CH-/Previous*LINE OUT*Answer/Reject phone; Frequency point/Car battery voltage/On load current*Led display*Microphone*Screw of rotation axis*Cigar end DC 12-24V*USB output:5V/2. 1A*Working temperature:0~50 C*Charge identification: support*Support play format: MP3*Storage battery display accuracy:error /-1V*Loaded current accuracy: /-0. 1A*SNR: