... ch home theater 2.RMS:30W+10W*2 3.Speaker unit:4"+3"*2 4.Electroplating Knob 5.Support usb ,sd card , ... . With Karaoke function,2 microphone socket input5. Volume, bass, treble, echo, mic-volume separately control6. Compatible with PC/VCD/DVD/CD ... mini speaker, SD card speaker, hi fi speaker, usb laptop speakers, SD speaker about 50000 pcs per month. 2.1channel multimedia speaker with remote control