The CML 100 is a Surface mount Back Electret condenser microphone used on the CLS100 visitors unit for the 2 Way security system. Specifically designed for high class speech. Cardioid polar pattern, frequency response 50 Hz - 18 KHz +/-3dB, sensitivity -47dB +/- 3dB @ 1KHz (0dB =1V/Pa), total harmonic distortion (THD) at an operating level of 125dB less than 1%, impedance 1.8KOhms. Power requirements 1.5 – 9VDC. Must be used in conjunction with Staff unit CSU100 and the complete 2 way Communicator intercom system.