The M504A includes a large display with full dot matrix characters that can easily be read in any lighting conditions, and a large knob for fast and easy channel selection. M504A has a built-in 25 watt PA and accepts an optional full-control  CommandMic III™ or selective-control CommandMic II™. Built-in ITU Class D DSC watch function monitors DSC Ch 70 activity, even while you are on another channel. Features a microphone connection at the rear panel instead of the face, and includes a 20' Extension Cable for a clean remote mic installation.

Channel Selection: Large rotary knob Controls: Volume knob, squelch knob, channel knob, backlit push buttons Mic Controls: Channel up/down, 16/9, hi/lo power Display Type: LCD with dot matrix Scanning Modes: Tag, programmable Weather Alert: Yes Receiver Performance: Sensitivity: Less than .22µV; Rejection: 80dB NMEA Interface: DSC, GPS input, NMEA 0183 GPS in/out, 25W hailer, CommandMic II™ or CommandMic III™ Dimensions: 6-1/2"W x 4-3/8"H x 3-3/16"D Draw: 6.2A (transmit)/1.5A (standby) Waterproof Rating: IPX8 Warranty: Three-year waterproof

• Enabling Your VHF Radio’s Safety Features
• Selecting a VHF Fixed-Mount Radio
• Selecting a VHF Handheld Radio
• Suggested Cruising Gear
• Selecting a VHF Antenna