The Telex MCP90 is a gooseneck electret condenser microphone, designed for front panel connection to that company's RTS, and several Audiocom, wireless or wired intercom main stations.
The wide frequency response and cardioid pickup pattern of the MCP90 allow for optimal speech intelligibility and minimal ambient intrusion. The unique, custom-threaded 1/4" TRS connector allows the microphone to be secured in a screw-like fashion to a main station front panel; the requisite phantom power is provided by the host station, and the mic will operate successfully within a wide 1.5 to 9 Volt range.