... 3"*2 4.Electroplating Knob 5.Support usb ,sd card ,vfd display Features:1. Built-in USB ... and SD memory card function, Support MP3 music format2. ... 4 inch,satellite3inch*23,Frequancy response:40HZ-20KHZ4,S/N:<70dB5,Dimension:wooferW270*225*225mm,satellite98*130*222mmPackage: ... home theater system speaker ,With usb ,sd ,vfd display, fm , karaoke , mini remote function