1, Support USB and SD card. 2, Support FM Radio function 3, Sensitivity: 290mv 4, Warranty: 3 years USB+SD ... Card+FM Radio Tube Amplifier HI-155FEATURESHI series tube amplifier have reliable quality ... outer carton 420x350x290mmGross weight12.00kg Naphon : USB+SD Card+FM Radio Tube Amplifier HI-155