Features:1.FM Transmitter for Samsung Galaxy S4/S3 and other MP3 / 4 players， mobile phones.2.Hands free talk function offer you more safety during driving.3.LCD displayers frequency with backlight.4.With Touch key design， High fidelity stereo.5.Digital PLL， transmission is stable in different environments.6.Full frequency range.7.Memory for last frequency.8.Powered by rechargeable built-in lithium battery， do not need to use the iPhone's power.9.Come with a Car Charger!!! More convenice!!!How to use:1. Connect this device to the compatible mobile phone or other audio device.2. Tune the frequency of the device to the same as the car radio. Play your music and enjoy via the car stereo3. Press the answer key of your mobile phone when the phone rings to answer calls， then talk hands-free via the built in high quality microphone and the car stereo.4. For optimal voice clarity， a distance of 30-60cm between the user and microphone is advised.5. If distortion or significant noise occurs， please tune down the volume of the mobile phone and tune up the radio.6. If the FM signal is interrupted please reset the car radio and the device to another clear frequency.Included1 x FM Transmitter1 x USB to Micro USB Cable1 x Car Charger