1、Wide application ranges. Suitable for Public inspection law interrogation room, prison, finance, education (5 ‑ 100㎡ adjustable). 2、High sensitivity, low noise, very low power consumption, power supply polarity protection circuit. 3、Signal transmission distance is approx. 1000m/1096yd. Frequency response is 20Hz ‑ 20kHz. 4、Connection method is 3‑wire system. Red is connected to power positive pole, black is connected to public GND, white is connected to audio positive pole. 5、An electro‑acoustic instrument that amplifies sound by receiving sound vibrations. 1 x CCTV Microphone1 x English Manual Item Type: CCTV MicrophoneMaterial: ABSUse place and area: Public inspection law interrogation room, prison, finance, education (5 - 100㎡ adjustable)Signal Transmission Distance: Approx.1000m/ 1093.6ydFrequency Response: 20Hz - 20KHzPointing Feature: Full pointingOutput Signal Amplitude: 2.5VPP / -25dBConnection Mode: 3 Wire system(Red is connected to power positive pole, black is connected to public GND, white is connected to audio positive pole)Transmission Cable: RVVP3 x 1.5mm²Power Supply Voltage: DC 12V