This professional high-fidelity low noise microphone is a great accessory to your audio surveillance system. Its low-noise high fidelity profile means it's ideal for high-traffic areas such as schools, banks, and factories, with an output impedance of 600 ohm and a frequency range of 100-100KHZ. The monitoring scope reaches 262 sq ft. Easy to install, this microphone can be used with both video recorders and IP cameras.