The M604 is the ultimate VHF. It features superior receiver performance, a large LCD with dot-matrix characters, 30 Watt 2-way hailer capability, and submersible construction. If you demand the best, the M604 is for you. Features include: Dual/tri-watch function for monitoring Ch.16 and/or call channel, 7 levels adjustable backlit display and keypad, Optional voice scrambler, UT-112 for private communication, Weather channels with weather alert function, and an AquaQuake draining function ...