Main control IC: AC 6921; Bluetooth IC: AC 6921 Bluetooth version is 5.0 Music format: MP3/WMA/WAV/FLAC/APE lossless format Bluetooth calling function; recording function; Folder switching function Radio FM frequency: 87.5-107.5 MHZ Support function introduction: support MP3 / USB / TF / LINE IN / FM / BLUETOOTH / remote control connection / DC 12V Button and interface function 1. PREV: Twist to the left to select the previous song; : Twist right to select the song; 2. IR: infrared receiving module; 3, MIC: support call and recording functions; 4. USB interface: connect U disk (maximum support 32GB); 5. LCD screen: synchronous display of lyrics; 6. SD card slot: connect SD memory card (maximum support 32GB); 7. AUX interface: audio input interface; 8. Volume knob: control the volume; 9. REC: Press and hold the REC button to start recording, press the REC button again to cancel the recording function and play the recorded file; when recording, you need to connect a storage device, such as a U disk or TF card; 10. REPEAT: Press the single loop function once, press it again to cancel the single loop, and play it in sequence; 11. -: The short key is to switch to the previous folder, and the long press is to rewind; 12. +: Short key is to switch to the folder, long press is fast forward; 13. PLAY/PAUSE: Short press is to switch between pause and play; long press is to radio FM automatic station; 14. MODE: Switch between USB / TF / FM / AUX / BLUETOOTH; Material: plastic colour: black Package Contents: 1 x decoder board 1 x remote control 4 x lines Only the above package content, other products are not included. Note: Light 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.