Vol-Button (Previous Song/Volume Decrease): In Mp3 State, Vol-Short Is The Previous Song, Long Is Volume Reduction; In The Fm State, Short To Adjust The Station Number Upwards; Under The Bluetooth Function, Short Is The Previous Song Of Bluetooth, And Long Is Volume Reduction; Double-Click To Cut To A Folder. Scan Button (Play/Pause): In Mp3 State, Auto Short To Play/Pause; In The Fm State, Short Is Automatic Retracting And Storage Table, Long Has No Function; Short Under Bluetooth Function To Play/Pause. Vol+ Button (Next Song/Volume Increase): Vol+ Short Is Song In Mp3 State, And Long Is Volume Increase; In The Fm State, Short To Adjust The Station Number Down; Under The Bluetooth Function, Short Is Song Of Bluetooth, And Long Is Reduced Volume; Double-Click To Cut Down A Folder. Mode Button: Switch Between Usb /Tf/Fm / Line In / Bluetooth Function; Long Is The Recording Function, The Button Again To Cancel The Recording Function And Play The Recording File; When Recording, It Is Necessary To Connect A Storage Device, Such As: U Disk Or Tf Card. Type:MP3 Decoder Board Power:2 x 25W Model:JQ-D011BT Function:Bluetooth Decoder Description Of The Recording Function: When Recording, It Is Necessary To Connect A Storage Device, Such As: U Disk Or Tf Card Colour:As Shown Material:ABS+FR4 Size:10.8x2.6x2.5cm Package Contents: 2 x Decoder Board 2 x Remote Control 2 x Cable 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.