?How to connect the Bluetooth FM transmitter?: 1. Tune your car's FM to a blank channel (A channel without any broadcast) between 88.1 and 107.9 MHz. 2. Plug NX10 into your car's cigarette lighter. It will turn on automatically and display your battery level. When the Bluetooth icon flashes, turn the knob to set the FM transmitter's frequency to the same channel. 3. Bluetooth Connection: Enable your device's Bluetooth. Search "NX10" and connect it, or play music directly from a U disk. ?Safety Functions?: Safety first. NX10 is equipped with a voltmeter to show you the condition of your car battery. Voltage should be between 13. 2V to 14. 7V when your car is on and moving. 12. 2V to 12. 8V when your car is parked and ignition is off. IC:26752-NX10. HVIN:NX10. ?7 Color LED Backlit Version?: Supporting 7 colors led backlit light, including Red/ Green/ Blue/ Yellowish Green/ Purple/ Cyan, this Bluetooth fm transmitter will give you a visually stunning display of colors, which is a nice way to match the colors already in the car. ?Enjoy Hands-free Calls?: Nulaxy technology provides a stable connection and echo-cancellation can reduce background noises for better hands-free calls, so you can answer phone calls with a press of the button. ?Crystal Clear Music Streaming?: You can stream music on your car stereo via Bluetooth/ USB Flash Drive (=32GB) / microSD Card (=32GB). Advanced noise reduction technology will ensure quality, crystal clear sound. Note: WMA MP3 WAV APE FLAC music formats in USB flash drive or microSD card are supported. ?Quick Charge 3.0?: Possibly the latest, fastest and most efficient USB charging technology in the world. Up to 4X faster than standard chargers, it is able to charge compatible devices to 80% within 35 minutes.