1.MODE: USB / TF / FM / LINE IN / BLUETOOTH; 2.REPEAT: Press once to cycle through , press again to cancel cycle through ; 3.EQ: sound field mode, test 6 kinds of sound quality; (classical) (jazz) (rock) (subwoofer) (pop) (normal); 4.LED: digital screen display, showing yellow; 5./ : short press is to select the song; long press is to increase the volume; 6.PREV / -: short press is to select the previous song; long press is to decrease the volume; 7.PLAY/PAUSE: short press is the switch between pause and play; long press is the radio FM automatic station; 8.USB: connect U disk (maximum support 32GB); 9.TF: Connect TF memory card (up to 32GB) 10.IR: infrared receiving module; 11.LINE IN: audio input interface; Color: black + gold Material: ABS Master IC: AC6926 Bluetooth IC: AC6926 Bluetooth version is 5.0 Music format: MP3 / WMA / WAV / FLAC / APE lossless format Radio FM frequency: 87.5-107.5 MHZ Support function introduction: support MP3 / USB / TF / LINE IN / FM / BLUETOOTH / remote control About the structure: panel size: 78 x 53 MM, the screw holes are located around the panel, and then the surface is covered with PVC lenses, the depth of the board is 23MM Package contents: 1 x MP3 Decoder Decoding Board 1 x Remote Control 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.