ER3050X Features Flexible metal hose， suitable for all vehicles  As soon as the auto starts， screen displays its battery voltage   Play music from USB disk and TF card reader Audio/music playback via Bluetooth A2DP， supports Bluetooth HFP/HSP， OPP， A2DP/AVRCP， PBAP profiles  Voice prompts the caller number when a call comes in  Support MP3 music format Full duplex， dsp (digial signal processing) technology， CVC technology for echo cancellation noise suppression  Charge for iPhone， Samsung， Nokia and Motolora  General Specs Bluetooth Version V2.1+EDR Rated Voltage DC 9-16V Bluetooth Profiles HFP/HSP， OPP， A2DP/AVRCP， PBAP Power Consumption <1W Work Temperature -10-70 degrees Format of Audio MP3/WAV/SBC SNR 68dB Distortion <0.1% Left & Right Channel >60dB Bluetooth Transmission Distance 5m Humidity 0-95% Frequency of Transmission 87.5-108MHz Frequency Response 20Hz-15KHz Package Details Weight: 184.04 g Size: 22*9.5*5.5 cm