... 3. Supplier with highest quality professional in-ear stereo earphone MP4.Specification:1.Speaker: 10mm2.Frequency response: 20Hz-20,000Hz3.Impedance ... : 1.2mFeature:1.fashional design,stereo,various color for mp3,mp4 player and mobile phone and iphone ,ipod … 2.advantaged ... all kinds of earphones, which are specially using for mp3,mp4 players, computers and mobile phones,etc.Types of earphones: main ...