Vol-Button (Previous Song/Volume Decrease): In Mp3 State, Vol-Short Press Is The Previous Song, Long Press Is Volume Reduction; In The Fm State, Short Press To Adjust The Station Number Upwards; Under The Bluetooth Function, A Short Press Is A Bluetooth Previous Song, And A Long Press Is A Volume Reduction.Scan Button (Play/Pause): In Mp3 State, Scan Short Press To Play/Pause; In The Fm State, Short Press Is Play/Pause, Short Press Is Automatic Closing And Saving Station; Short Press Under Bluetooth Function To Play/Pause.Vol+ Button (Next Song/Volume Increase): Vol+ Short Press Is The Next Song In Mp3 State, And Long Press Is Volume Increase; In The Fm State, Short Press To Adjust The Station Number Down; In The Bluetooth Function, Short Press Is The Next Song Of Bluetooth, And Long Press Is Reduced Volume.Mode Button: Switch Between Usb / Sd / Fm / Audio Input / Bluetooth Function. Long Press Is The Recording Function, And The Recording Audio Source Is Input To Line In. Radio Fm And Bluetooth.When Recording, You Need To Connect A Storage Device, Such As A Usb Flash Drive Or Tf Card Type: MP3 Decoder BoardModel: JQ-D122BTFunction: Bluetooth DecoderColour:As ShownMaterial:ABS+FR4Size:11.2 x 2.5cm Package Contents:1 x Decoder Board1 x Remote Control1 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.