Dual USB Ports Car Charger: This Bluetooth FM Transmitter Car Music Player comes with two USB ports (5V-2.4A and 5V-1A) that allow you to charge two devices simultaneously. Additionally, one of the USB ports also allows you to play music from a USB disk while charging a device.3 Music Play Modes: The device supports three music play modes, including Bluetooth-enabled devices, SD card (up to 32GB), and USB flash drive (up to 32GB). It also supports various audio formats, such as MP3, WAV, WMA, FLAC, and APE.Hands-Free Calling & Navigation Broadcast: The device has a multifunctional button (MFB) that allows you to answer, redial, hang up, or reject calls with just one click. It seamlessly switches between incoming calls and music. Additionally, it supports navigation apps on your phone, allowing you to navigate without looking down at your phone for safer driving.Car Battery Voltage Detection & Blue Ambient Light: The Bluetooth FM Transmitter Car Music Player displays the car's voltage when plugged into the cigarette lighter, allowing you to keep track of the car's battery health at all times. The device also has a blue backlight around the car charger, making it easier to use while driving.Wider Range & Compatibility: This Bluetooth FM Transmitter Car Music Player is compatible with various wireless Bluetooth-enabled devices such as Samsung, HTC, Blackberry, Sony, tablets, and MP3/MP4 players. It also has a wider frequency range of 87.5MHz - 108 MHz, ensuring a more stable and interference-free music experience.