In ear earphone 1,Powerful drive unit: 9 mm diameter 2,Sensitivity: 100dB/mW 3.Power: 100mW 4.Stereo-sound 1, Powerful, bass-driven stereo-sound ... 2, Perfect fit in the ear canal and good attenuation of ... : 6-23, 000Hz 10,To bear the greatest power: 100mW In-ear earphone