The RTA-M Reference Microphone from dbx is an omnidirectional mic designed for use with dbx DriveRack series real-time analyzers (sold separately) to provide an acoustic picture of a room. It can be used to capture audio and fine-tune your sound system performance to match the response characteristics of the room for live sound and recording applications. In addition, the RTA-M is built with a metal housing, requires phantom power (9 to 52 VDC), and includes a mic clip along with a hardcover case.