Miniature boundary microphone for installation in security, ambient monitoring and observation applications. Output level is variable from -50dBv (3.2mV) to -10.5dBV(300mV) at 1?Bar which is designed to interface with security cameras, digital video recorders and other observation and recording devices. Internal audio limiter circuitry tames high sound pressure levels and improves intelligibility by protecting the audio signal from distorting sensitive recording circuitry in cameras and digital recorders.