... frequency response range: 30HZ 16000HZMicrophone operating voltage: 3v Back hang earphone – back hang design, portable, gloss surface treatmentMain features:1, black ... gloss design, simple style2, back hanging earphone, light design, easy to wear;3, hi-fi speakers, pure ... plugs, pure sound quality.7, sponge earmuffs, fresh, anti-sweat. Neck-band Headphone H820