Standard Horizon VLH 3000A 30W Dual Zone PA Loud Hailer Fog w Listen Back & 2 Optional Intercom Stations MLA Format Guide: Steps, Examples & Templates PaperCheck PaperCheck. VLH 3000A 30W Dual Zone PA Loud Hailer Fog w Listen Back & 2 Optional Intercom Stations 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