This is an indoor microphone with 5m²-50 m² listening range. It has the design of miniature SMD, can adjust the sensitive, with high fidelity, clear sound quality and concealment installation. With the advantages like low noise, wide operating voltage range, low power consumption and long transmission distance, it is suitable for banks, prisons, examination room, shopping malls and industrial site, etc. It is the ideal product for CCTV surveillance and security system. It can be used with camera to achieve synchronization of audio and video.