Feature: Support MP3 or WMA or WAV or FLAC or APE Support: MP3 or USB (U disk) or TF or LINE IN or FM or BLUETOOTH Power Supply: 5V 12V Three buttons: PREV or PLAY or NEXT With FM: Support FM Radio function 1. PREV button (previous song or volume reduction): In the MP3 state, the PREV short press is the previous song, and the long press is the volume reduction 2. PLAY button (play or pause): PLAY short press for play or pause in MP3 state long press is USB or TF card or AUX or Bluetooth mode test tone switch. 3. NEXT button (next song or volume increase): NEXT short press for song in MP3 state, long press for the volume to increase 4. This model has the function of automatic conversion device. When there is no device, the default is in the Bluetooth state. If there is a device, the device is interpreted first. TF: Connect TF memory card (up to 32GB) USB: Connect USB flash drive (up to 32GB) LED indicator PREV or VOL-: Short press is to select the previous song long press is to decrease the volume PLAY or PAUSE: Short press is the switch between pause and play Long press is the switch of USB or TF or FM or AUX or BLUETOOTH sound, in the radio FM state, the short pause play button is automatically searched NEXT or VOLand: Short press is to select song long press is to increase the volume Material: plasticandmetal colour: Silver Package Contents: 1 x DIY 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.