Vintage Radio Shack Duofone Electronic Telephone Amplifier Model 43-278.

Hello Angels,

Once upon a time, there were three little girls who went to the police academy.

Remember that TV show Charlie's Angels? It was a television hit after the debut of its first season in September 1976. The show was the hottest thing on TV. A speakerphone was used to give the angels there assignment.

Tested, Works!