Bluetooth Function Model: AK 403On/Off Power Switch USB & SD Input(MP3 Player) Three Small Speaker Drive Units: 6.5"*1+3"*3;6.5"=35W;3"=5W With FM Radio Dimensions: 442(L)x373(W)x387(H)MM Inpedance: 8 ohms Total Output Power: 45W Frequency Response: 38HZ-20KHZ Distortion: 0.3% at 1W S/N: >70db Separation: >4 Colour: Black