CRYSTAL CLEAR SOUND -- Incorporating CVC noise suppression technology, FM transmitter efficiently reduces the background noise to deliver CD-Like quality sound with deep bass and no static. Built-In microphone with echo cancellation allows you to take hands free phone calls without distraction from drivingSTABLE TRANSMISSION -- Advanced Bluetooth 5.0 technology maximizes device compatibility, pair speed, data transmission rate and connection stability between car FM transmitter and Bluetooth device compared to old version Bluetooth 4.2, 4.0; It is sufficient to stream your music flawlessly in your carMULTIPLE MUSIC PLAYING MODE -- Bluetooth connection allows wireless streaming of music from portable devices. SD card slot for playing music or audio books from SD memory cards; USB port music playback in MP3 and WMA formatsFAST CHARGING -- QC3.0 smart fast charging, Type-C fast charging, dual USB expansion three devices can be charged at the same timeSAFETY -- LED dot matrix screen, real-time monitoring of battery voltage, Below 12.0V, the battery needs to be replaced, there is a danger of short circuit and fire