product description:support MP3 format, automatically play, play the status of the red LED update.support U disk (tested over 32G), TF card (tested 16G) playback mode; default TF card mode, if the TF card does not exist automatically jump to U disk mode, and both devices are installed, you can manually Set the playback mode, please refer to the keyoperation instructions.button to adjust the up and down track switch, volume + -, pause / play, mode switch,Note:"long press" time about 2SIf you use U disk mode, the proposed 5V supply, some U disk does not support 3.7V supply.Product specifications supply range: 3.7 ~ 5.5VProduct Size: 45mm x 36mmExquisite double board design, area copper, stable and reliable.Anti-static bag refined packaging, to avoid damage to the way of delivery static electricity.Material: metalcolour: bluePackage Include:2 x Mp3 lossless decode boardOnly 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.