§ Compact sensitivity can be adjusted
§ Senior microphone suppress ambient noise
§ independent broader mining tone into the audio port
§ Built-in noise reduction processing circuit
§ power polarity protection circuit
§ Waterproof external microphone design

20 to 80 m2
Impedance 600 ohms
Frequency of 200 ~ 10Khz
Power 9 ~ 14VDC
Size 39 * 31 * 18mm
For HaiKang, Dahua DVR device