The GMR 404 is 4-foot scanner with 1.8° beamwidth and a 72 nautical mile range. With this bandwidth and 4 kilowatts of power, it offers outstanding clarity, precision and target definition. Communicates with the Garmin Marine Network through a waterproof 100-megabit plug-and-play proprietary network — It also comes with carrying strap, field material kit, marine network data card, field install cable end kit, printed material kit.The GMR 406 "big sweep" is a 6-foot scanner with 1.1 ° beamwidth and a 72 nautical mile range and the same features as the GMR 404. Comes with the carrying strap, field material kit, marine network data card, GMR 404/406 cable, field install cable end kit, and printed material kit.