The KECG2742PBL-A from Kingstate is an electret condenser microphone. An electret microphone is a type of electrostatic capacitor based microphone, which eliminates the need for a polarizing power supply by using a permanently charged material.
Sensitivity is -42dB
Operating voltage is 2VDC
Impedance is 2.2Kohm
Rated voltage is 10VDC
Sensitivity reduction is -3dB at f=1KHz, 1Pa, Vs=2.0VDC. to 1.5VDC
Frequency range from 20Hz to 20KHz
Maximum current consumption is 0.5mA at Vs=2.0VDC, RL=2.2Kohm