... :4"+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 ... 1,Output power:30W+10W*2(RMS)2,Speaker driver:woofer 4 inch,satellite3inch*23,Frequancy response:40HZ-20KHZ4, ... 40HQ 2.1 Piano home theater system speaker ,With usb ,sd ,vfd display, fm , karaoke , mini remote ...