This model has the function of automatic conversion device. When there is no device, the default is in the Bluetooth-compatible state. If there is a device, the device is interpreted first. Music format: MP3/WMA/WAV/APE/FLAC lossless format Radio FM frequency: 87.5-107.5 MHZ Support function introduction: support MP3 / USB / TF / LINE IN / FM / Bluetooth-compatible 5.0 / remote control Panel size: 5x2.4cm TF:Connect TF memory card (up to 32GB) USB:Connect USB flash drive (up to 32GB) (Shipment without card) LED indicator PREV/VOL-: Short is to select the previous song; long is to decrease the volume. for PLAY/PAUSE: Short is the switch between pause and for play; Long is the switch of USB / TF / FM / AUX / Bluetooth-compatible sound, in the radio FM state, the short pause for play button is automatically searched. NEXT/VOL+: Short is to select song; long is to increase the volume. Support MP3/WMA/WAV/FLAC/APE Support:MP3/USB (U disk)/TF/LINE IN/FM Power Supply:5V 12V Three buttons:PREV/for PLAY/NEXT 1. PREV button (previous song/volume reduction):In the MP3 state, the PREV short is the previous song, and the long is the volume reduction. 2. for PLAY button (for play/pause):for PLAY short for play / pause in MP3 state; long is USB / TF card / AUX / Bluetooth-compatible mode test tone switch. 3. NEXT button (next song / volume increase):NEXT short for song in MP3 state, long for the volume to increase. Note:The colors and styles of accessories are random due to different batches and cannot be specified. Colour:Silver Material:ABS Package Contents: 1set * Car MP3 decoder board 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.