It's easy to use, plug the transmitter into your phone or other device, and set the transmitter to the same channel as the car radio. With a launch distance of 15 meters, it is the most powerful transmitter.Features:1. FM transmitter, suitable for iPhone/iPod/HTC/MP3/MP4 player and most devices with 3.5mm audio jack.2. Built-in 300mAh rechargeable battery for 10 hours of continuous playback. You can enjoy your favorite music on the trip without any worries.3. Supports FM's last frequency memory function and uses PLL phase-locking technology to ensure stable output under all conditions.4. Support hands-free call through car stereo speakerphone for safe driving.5. Built-in digital tube display, easy to read, will not cause distraction in the car. Left and right buttons to adjust the FM frequency, easy to use.6. Suitable for iphone series/ipod series / Nokia /Ericsson/HTC/Motorola/Dopod/Xiaomi/LeTV, MP3/MP4/MP5, computer, etc. As long as there is a 3.5MM headphone jack interface machine.Specifications:Charging: 5V 1A (4.75V-5.5V 1A 10%)AUX connection: 3.5mm audio connectorFM display: 88.1Hz-107.9HzFM connection: the same frequency is connectedAudio input: 3.5mm audio connectorVolume adjustment: noneSwitch: ON-OFF switchAudio output: FM band connection outputFrequency adjustment: press ">" to increase the frequency "<" to decrease the frequencyOutput voltage: 5 0.1Vehicle current: 600mAStorage temperature: -20 C ~ +50 CWorking temperature: -10 C ~ +40 CStereo resolution: 38dBPackage List:1 * User Manual1 * Charging Cable1 * TransmitterNote: The hands-free function is not based on the microphone of this transmitter. The transmitter itself does not have a microphone. Plug this transmitter into the phone and use the phone's microphone to make a call. Fast connection and operation, as long as the vehicle frequency and transmitter frequency are the same (do not exclude external strong interference). Please use this product to debug several frequency points and find the most suitable local channel. The channel should not conflict with the local radio frequency. It is best to choose a blank FM channel. The optimal channel is different in different regions..