... specifications : 1, EM-403 dynamic CB mic2, electret unidirectional CB mic 3, CB mic with 4 pin 5 pin 6 ... ,cable extended length 2.3mparameterB Microphone microphones for CB mobile radios Sensitivity-66+3dB at 1K HzImpedence500 ohmFrequency response100- ... required . About us :We are the professional CB radio products , CB micophone , CB speaker and two way battery manufacturer . integrate research ...