GTE Autovon digital secure voice terminal

1982

GTE · Military, American · Source/via: JKL Museum of Telephony (website)

GTE Autovon digital secure voice terminal

About This Phone

For use with the U.S. Autovon military phone system.

Wikipedia

The Automatic Voice Network was a worldwide American military telephone system. The system was built starting in 1963, based on the Army's existing Switch Communications Automated Network (SCAN) system.