This multi function are designed for driving use, with this small device you can stream music and calls directly from your device to your car FM stereo system. Make your driving more safe and enjoyable. Multi-function, such as , hands-free calling, music playing. Two extra USB ports let the users can charge their personal digital device and play USB Drive music on the same time. Feature - Color: As Shown. - Material: Plastic+LCD+Electronic Component. - Size: 8 x 5 x 11cm. - Working voltage: 12V-24V - Output : 3.4A (dual USB smart ) - Output voltage: DC/5V - Transmission frequency: 87.5 ~ 108MHZ - Display: Digital tube display - version: 4.2 - Effective distance: about 10m - Launch distance: - Support for expansion: U disk - This product has the integrated functions of , car mount MP3,USB charger and audio output,etc. - Moreover, as long as your mobile phone is equipped with , you can transfer the music from your mobile phone to your car stereo. - Calls can be switched to the hands- . At the end of the call, the music will be automatically switched to play. - USB output voltage, which can charge 2 devices at the same time. - T-flash supported, let you use it more freely and easily. Warm Tip: Dear buyer, Due to lighting effect, monitor's brightness, manual measurement and etc, there could be some slight differences in the color and size between the photo and the actual item. Sincerely hope that you can understand! Thank you! Package list: 1 Signal Transmitter