4-Wire Terminals | 4-Wire Bridges| 4-Wire Parts & Repair
Often referred to as “Hoot and Holler” or “Shout Down” phones, our 4-wire systems are most commonly used by government agencies, nuclear power facilities, and many of the world’s largest financial institutions for private voice conferencing, urgent briefings, and emergency response.
We are the largest 4-wire equipment manufacturer in the world, and we also provide repair services, equipment replacement, and technical support for 4-wire systems in US and foreign markets. Hundreds of small and large scale networks rely on our 4-wire technology for essential communications. Some of our largest and most notable 4-wire networks include the National Warning System (NAWAS), East and West Coast Tsunami Warning Systems, and the FAA Interphone Network.