High quality stereo sound radiation proof anti rad

Specification: Electret condenser microphone Offset: 4.5VDC 2.2Kilohm Sensitivity: -42 ±3dB f=1KHz, spL=1Pa Directivity: omni directional Static impedance: 1-2.2Kilohm Peak voltage: 10VDC Distortion: at 400Hz and 1KHz less than 5% Speech to noise ratio: more than 58dB Horn Sensitivity: 114±5Db SPL/3MW/5cm at 1KHz Range of frequency: 20Hz-20KHz Resistance: 32Ohm±15% Rated power: 3mW Capacity: 5mW Lead wire length: 1-1.5m The radiation of mobile phone is harmful to our health, this is a specialized radiation proof earphone.It is suitable for allmobile, MP3 and MP4 player.