Features 30W PA/Hailer output with Listen Back Dual Zone Forward, Aft or Both 6 Preprogrammed Fog Signals Underway, Stop, Sail, Tow, Anchor and Aground Horn and Siren Noise canceling microphone with dedicated CALL, IC1 and IC2 keys Compatible with MLS-300 and MLS-310 10W amplified external audio speakers Compatible with optional MLS-300i intercom speaker with Push-to Alert button for IC1 and IC2 Flush Mount capable with optional MMB-84 Adjustable Backlight 3 Year Waterproof Warranty Features 30W PA/Hailer output with Listen Back Dual Zone Forward, Aft or Both 6 Preprogrammed Fog Noise canceling microphone with dedicated CALL, IC1 and IC2 keys Compatible with MLS-300 and MLS-310 10W amplified external audio speakers