P-X8 submersible, plug-and-play connectivity, controls all function (including DSC) of Icoms IC-M504 or IC-604 VHF marine radios. Large LCD with adjustable lighting level. Doubles as an intercom. IC-604 accepts up to 2 COMMANDMICIIIs. It's like getting a second (or third) on-board radio station for the cost of an accessory. Instructions for using the COMMANDMICIII are included as part of the M504 and M604 instruction manuals. The COMMANDMICIII (HM-162B/SW) remote-control microphone size (W + H + D): 65.5 + 150 + 38 mm; 2.5 + 6 + 1.5 in. Weight (approx.; except cables): 13.6 oz. Supplied accessories, 6.1m (20ft) of cable, OPC-1540, with external speaker terminal, Microphone hanger, Mounting base for cable connector.