This device is a Bluetooth Mp3 player for car-used, which equipped with professional high-performance Bluetooth module and Mp3 decoder chip.It can transmit the music from TF card to car stereo via FM radio signal.It can transmit your mobile phone's music to car stereo via Bluetooth.It can also be used as a hands-free car kit during driving.This device transmits signal by wireless method, no need to modify anything in car. It can be used both as the music player in entertainment purpose or hands-free car kit safety purpose during driving. Product Introduction1. Support Bluetooth hands-free phone calling via its build-in microphone.2. Noise and wind suppressed by CVC technology to create full duplex sound quality.3. Support mobile's A2DP function. Music will be played directly while the mobile phone is connected.4. Mobile phone can be connected automatically when the device turns on.5. Support an external TF card, can play music files in Mp3/WMA format.6. Integrated car charger of output 5V-1500mA, is available for charging handheld devices in car. Type: FM TransmitterInput Voltage: 12-24VOutput Voltage: 5V +/- 0.25Output Current: 1000mA (Max)Power consumption: 1WOperating temperature: 0-50 degreesSupport playback format: MP3 WMA (option) Bluetooth:Bluetooth Version: V4.1 + EDRFrequency: 20HZ- 15KHZSensitivity: -42db +/ 3 db 360Voltage: 5V +/- 0.5Working Current: 45mA (Max)Stand-by Current: 25mA (Max)Frequency: 2.402 - 2.480ghzEffective Range: 5metersSensitivity: -92dBmRF Output: 4dBm Frequencies:FM: 87.5MHZ - 108.0MHZTransmitted Power: 87dBuv / 107dBuv