41 | Navigation, searching equipment |
412 | Decca, loran, omega, radio direction finder |
42 | Communication equipment |
421 | Radio plant, gmdss |
422 | Lifeboat radio transmitters, epirbs |
423 | Data transmission plants, communication |
424 | Vhf/uhf telephones |
425 | Calling/command/crew call telephone plants, walkie-talkies |