I used this mic 2 times, am selling it because I bought the Sonarworks software package that includes a calibrated microphone. The case arrived cracked and I fixed it with crazy glue. The PRM1 Precision Reference Microphone is a special type of microphone that provides an accurate reproduction of a room's sound characteristics for use with audio-analysis tools. It employs a ¼”, pre-polarized electret-condenser capsule with an omnidirectional polar pattern, which allows the microphone to measure reflections, as well as direct signals up to 132 dB SPL. The PRM1 has an all-metal chassis and comes with a clip, foam windscreen, and hard case.