【5-in-1 Powerful Adapter】It can work as Bluetooth audio Transmitter, Bluetooth audio Receiver, USB U-Disk Music Player, TF/Micro SD Card Music Player and car Hands-free Tool. There is always a function that can do the job for you. (Note: Only one mode can work at a time, these modes can not work at the same time. When using the Bluetooth function, only one Bluetooth device can be paired at a time. It cannot pair two Bluetooth headsets or two Bluetooth phones at the same time). | 【With a Big Knob】You can use this knob to adjust the volume, Answer/Reject/Redial calls while driving. The LED light around the knob not only make it look very beautiful, but are also very convenient to use at night. | 【Built-in Battery】You can use it in any situation even without AC outlet. It can be fully charged in 1-2 hours and last for 6-8 hours, perfect for all-day listening or long road trips, you also can use it while charging. (Note: Power adapter is not included, pls charge it via your device's USB, car charger or your own 5V USB power adapter) | 【Large LCD Screen】With this display screen, you can see the mode and status information: TX, RX, USB, TF and Volume Level, which is a special feature among similar products. | 【Multiple Playing Modes】Supports U-disk/USB flash drive and TF/Micro SD card to play music, supports mp3/wav/wam/ape/flac audio formats, powerful audio decoding capability, let you play your favorite high-quality music anytime, anywhere without internet connection. (Note: Does not support NTFS, please format the U-disk or TF/Micro SD card to FAT32 or exFAT in your computer before using it to this adapter). | Note: Make sure your headset/earphones/airpods/soundbar/speaker's Bluetooth is not connected to any other device, and they are need to be set into pairing mode, Otherwise, you can't connect. For example, Disconnect airpods from your iPhone, close the lid and flip it open again, Press & Hold the button on the back of the charging case until the little LED light starts flashing WHITE, which means it’s in pairing mode.