ER3001B Features Talking in hands free LCD display， song name， track， calling number display Excellent sound quality with D.S.P solution for echo cancellation noise suppression (CVC) Broadcast music stored up by the automatic through car stereo system Support USB disc.SD card Support MP3/WMA music format Full duplex， dsp (digial signal processing) technology 21 keys remote controller and steering remote controller Wireless audio transmission Line-out 3.5 mm Apply to any 3.5 mm interface audio play device， such as CD， MD， MP3， MP4， PDA， Tablet PC， notebooks General Specs Limit Voltage 9-26V Power Consumption 1W Work Temperature -20-50 degrees Format of Audio MP3/WMA SNR >60dB Distortion 0.10% Bluetooth Version  V3.0 Bluetooth Transmission Distance 10-15m Range of Mic 0-2m Frequency of Transmission 87.5-108MHz Frequency Response 20Hz-15KHz Charging Output DC 5V 1A Package Details Weight: 210.79 g Size: 23.5*13.3*5.5 cm