This device allows you to stream music and calls directly from your Bluetooth device to your car FM stereo system. The built-in microphone gives you amazing hands-free functionality. It also has USB and TF card slots, allowing you to stream your favorite MP3 music to your car's stereo system. Play music files from external devices by connecting your music device using the auxiliary input port. It can also charge your phone using dual USB charging ports. Its Bluetooth chip can be used in a variety of devices. feature1. Wirelessly transfer phone calls from a bluetooth phone to a car FM audio system. 2. Dual USB ports can charge other devices, and multiple electronic devices can be charged at the same time, such as Apple iPhone, iPod, iPad, Android, Samsung and other smart phones. 3. Automatically switch hands-free mode from music playing state when answering a call. 4. Support USB/TF/AUX-IN. 206 channels optional 87.5-108.0MHZ, with LED display5. Power from the cigarette lighter in the car (DC12V/24V) SpecificationFrequency: 87.5-108. 0MHZFrequency Stability: /- 10ppmlProduct input: 12-24VCharger output: 5V/2. 1AMusic format: MP3USB (maximum capacity): 32GBCard (max capacity): 32GBTransmission distance: about 10mWeight: 85gColor: black red material: plasticPacking size: 120*100*42MM Keywords: car transmitter, transmitter, bluetooth, fm transmitter, plastic material: plastic