Icom IC-M400BB SW Modular VHF Marine Radio with Black Command Mic IV. The IC-M400BB consists of a two-piece, black box configuration. All function control including DSC operation, can be made from the Command Mic IV, HM-195B/SW, and the RF unit, IC-M400BB, can be installed in an out-of-sight place. The new menu system is shared with Icom "s latest models. The bottom line of the dot-matrix display shows the software key functions which can be toggled with the left and right buttons. The built-in bidirectional active noise cancelling reduces background noise to up to 90% and improves both your transmitted voice and incoming call. Hear and be heard more clearly. The IC-M400BB has a built-in 10W amplifier that increases the audio output from an additional external speaker. The public address function allows you to make an announcement from the microphone like a loud speaker, and the foghorn can also be emitted from the external speaker. The built-in DSC watch function monitors Ch. 70 (DSC channel) activity, even while you are receiving another channel. DSC functions include: distress, individual, group, all ships, urgency, safety, position request/report, polling request and DSC test calls. When connected to an external GPS receiver, current position and time are shown on the Command Mic IV display. When receiving DSC information from another vessel, the radio can transfer it to a navigational device via NMEA 0183 connectivity. When connected to the optional MA-500TR Class B AIS transponder, the AIS target call function allows you to set up an individual DSC call from the MA-500TR. A