Multifunctional 4in1 car charger: This device combines a car charger, FM transmitter, MP3 player, and 0 connection in one compact unit, allowing you to charge your devices and enjoy music seamlessly. Realtime monitoring: Equipped with an LED display, it provides realtime monitoring of your car battery voltage and charging current, so you stay informed about your vehicle's power status. Compatible with multiple devices: for various digital products including mobile phones, tablets, MP3/MP4 players, cameras, and iPods, making it a musthave accessory for any road trip or daily commute. Lossless audio experience: Enjoy sound quality with lossless audio decoding that supports multiple audio formats such as MP3, your music sounds while driving. Use scenarios Road trips and long drives: keep essential devices charged while listening to music through the FM transmitter and MP3 playback. Daily commuting: monitor your car battery voltage and charging current in real time while keeping devices powered. Multidevice households: a convenient solution for phones, tablets, MP3/MP4 players, cameras, and iPods on the go.