¡ì fidelity low noise processing chip¡ì Senior microphone suppress ambient noise¡ì hemisphere shell sensitivity can be adjusted¡ì meeting room, hall, commonly used¡ì Built-in noise reduction processing circuit¡ì power polarity protection circuit10 to 100 m2Impedance 600 ohmsFrequency of 200 ~ 10KhzPower 9 ~ 14VDCSize ¦µ72 * 41mmFor HaiKang, Dahua DVR device