Crystal Clear Audio - The FM transmitter uses CVC noise reduction technology and effectively reduces background noise to deliver CD-like audio quality with deep bass and without static noise. Built-in microphone with echo reduction allows you to make hands-free calls without being distracted while driving. Stable Streaming - Advanced Bluetooth 5.0 technology maximizes device compatibility, pairing speed, data transfer rate, and connection stability between the car's FM transmitter and Bluetooth device compared to the old Bluetooth version 4.2, 4.0 is enough to stream your music seamlessly in your car. Multiple Playback Modes - Bluetooth connection allows wireless music streaming from portable devices. SD card slot to play music or audiobooks from SD memory cards. USB port to play music in MP3 and WMA formats. Fast Charging - QC3.0 intelligent fast charging, Type-C fast charging, dual USB expansion, three devices can be charged simultaneously. Safety - LED dot matrix display, real-time monitoring of battery voltage, below 12.0V, the battery must be replaced, there is a risk of short circuit and fire.