The Yaesu MD-100A8X desk microphone uses a cardioid dynamic microphone element. It features an UP-DOWN tuning control (on compatible Yaesu transceivers), a scan switch, a switch for PTT (push to talk) and also a lock feature. On the bottom of the microphone base there is a High Emphasis switch and a Low Cut Switch.
This is a 500 ohm microphone that works well with the FT-747, FT-757GXII, FT-840, FT-847, FT-897, FT-857, FT-890, FT-897, FT-990, FT-1000 and FT-1000MPV.
Note: It does not work on some older Yaesu transceivers such as the FT-736R.