Specification
Type Open air dynamic type (15mm) 
Sound pressure sensitivity 105+-3dB (1000Hz/mw)  
Microphone sensitivity  -62+- 3dB
Frequency response 50Hz~15KHz 
Impedance 32? +- 10%(Dc) 
Rate input 2mW 
Max input  10mW 
Plug size: 2.5mm plug /other mobile phone connector
Cord length  1.2m +- 50mm
Features >>  
1.   Extraordinary high performance 6um super-thin Mylar
      driver offers a full-range sound that is perfect for human
      speech. 
2.   Super sensitive microphone delivers high quality speech
3.   In-line microphone design and convenient in-line 
       on/off/mute switch control.
4.   Compatible with most 2.5mm plug cell phones.