* Independent 2-way microphone volume adjustment; * Auto setting oof treble, bass, echo and delay; * With Karaoke exciting effect; * 4-way optional input sound sources, 1 way output; * With high fidelity accessing switch; * Vivid Fluorescent Display(VFD), full function control; * Automatic memory to all data when power off; * OK870 + HF860 express the perfect music, karaoke effect.