Feature:1.This equipment can detect batterys voltage.2.Support bluetooth hands-free calls, built-in microphone, secure answer calls.3.Support mobiles A2DP function. Music will be played directly while the mobile phone is connected.4.Mobile phone can be connected automatically when the device powered on.5.Support an external TF card / U disk, can play music files in MP3 / WMA format.6.Integrated car charger of output 5V/2.5A, is available for charging handheld devices in car.Specification:bluetoothbluetooth Version: V3.0+EDRFrequency: 20h-20 KHZSensitivity: -42db+ / 3 db 360Voltage: 5V+ / -0.5Working Current: 45mA(max)Stand-by Current: 25mA(max)Frequency: 2.402-2.480 ghzEffective Range: 5 metersSensitivity: -92 dBmRF output: 4 dBmFrequenciesFM: 87.5MHz-108.0MHzTransmitted Power: 87dBuv / 107dBuvEffective Range: 2 metersInstruction:First Time to Use This Device1.The device turns on automatically when plugged the integrated. Car charger into car cigarette lighter hole.2.Select any of blank frequency between 87.5-108.0MHZ.3.Turn on car FM stereo and select the frequency same as that ofthe device.Package Included:1 X bluetooth Car Charger1 X Audio Cable1 X User Manual