Hands-free mobile phone calls, free your hands and drive safely High-fidelity stereo sound with digital PLL phase-locked loop technology LCD display with backlight to show frequency, more convenient channel selection Suitable for most brands of mobile phones and music players with 3.5mm headphone jack on the market FM full frequency transmitter: 87.5-108.0MHZ (up to 200 frequencies to choose from) Power-off memory to store the current frequency played The transmitter has a built-in lithium battery, which does not consume the power of your mobile phone. (Not Included Car Charger) Instructions for use: 1. Switch on the transmitter first, and the screen will light up. 2. Plug the transmitter into the 3.5mm headphone jack of your mobile phone or MP3/MP4 music player. 3. tune the transmitter to an empty frequency band (a frequency not occupied by the local FM radio station). 4. tune the radio in the car to the same frequency as the transmitter. 5. play music from your mobile phone or a music player such as MP3/MP4 and you can listen to music through the car stereo 6. Press the answer button on your mobile phone when a call comes in to make a hands-free call. Specifications: Effective transmitting distance: 10m FM band range: 87.5-108.0MHZ Distortion level: