Wireless FM transmitter for car with BT, USB charger & voltage display1、Built-in high-performance BT chip, intelligent noise reduction, lossless sound quality, clearer listening to songs and calls. 2、Support hands-free calls, built-in microphone, clear and smooth call, answer/reject/recall in one key. 3、With power-off memory function, automatic connection recovery after power-on, memorize frequency, more intelligent. 4、Dual USB and PD three-port charging output, more convenient to use. Support car battery voltage detection, safer driving. 5、Built-in multiple protections, overload conservation, over current conservation, over/under voltage conservation, over temperature conservation, short circuit conservation, etc. 6、Support TF card and U disk playback, plug and play, support MP3/WMA/APE/FLAC format. 7、It is suitable most 12-24V mainstream models on the market, with 7-color backlit, creating a cool ambient for you.