(This unit does not have a built-in amplifier; it features dual audio outputs and is suitable for car and amplifier retrofit installations): 1. DC 5V or 12V power supply (selectable; both voltages cannot be connected simultaneously), using a 12V 1A power supply; (We sell 7805 and 7812 voltage regulator modules, 220V to 5V and 12V 1A power supplies). 2. Supports infrared remote control. 3. Supports FAT16 and FAT32 file systems. 4. Supports MP1 Layer3, MP2 Layer3, and MP3 Layer3 versions of songs. 5. Can read MP3 songs from USB flash drives and TF cards. 6. Supports Bluetooth functionality; a USB Bluetooth stick needs to be purchased for use. 7. Dual-channel audio output, suitable for car and amplifier retrofit installations. Panel Function Description: 1. "TF" slot: Inserting an SD or MMC card containing MP3 songs will automatically play the music (a card adapter is required for TF cards). 2. Power indicator light: Illuminates when powered on and flashes during operation; 3. Remote control receiver; 4. "USB": USB flash drive port. Inserting a USB flash drive containing MP3 songs will automatically play the files; 5. "PLAY/PAUSE": Short press to play/pause in USB/SD mode; Color: As Shown Material: PCB Package Contents: 1*Decoder board module Kit Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.