Single Earhook Headset Mic with Screw Lock Connector 3.5mm Stereo for Sennheiser Single Earhook with 1/8"(3.5mm) Screw Lock Connector and Windscreen Polar Pattern : Omnidirectional Frequency : 50 Hz - 18,000 Hz Sensitivity : - 60 dB +/- 3dB, Operating Voltage : 1V - 10V DC Impedance : 1,500 Ohms +/- 30% (at 1 Khz)