VHF Marine Black Box Radio w/White Command Mic. Black Box Transceiver When Space Is At A Premium. Icom's M400BB is a VHF fixed mount with Class D DSC. The M400BB is a spacesaving unit, ideal for owners of compact boats and shipbuilders looking for a black box solution. The M400BB comprises only a black box main body and a supplied COMMANDMIC HM195 remote control microphone accessory. The two-piece radio set can easily be installed behind a wall or console-leaving a small or hidden footprint-and