73129841
Jun 10, 1977
Jan 24, 1978
SELF-CONTAINED PACKAGE FOR LOUDSPEAKER PAGING THROUGH PBX, PABX, OR KEY TELEPHONE SYSTEMS, WHICH IS UTILIZED IN ASSOCIATION WITH THE TELEPHONE SYSTEM WITHIN THE SUBSCIBER'S PREMISES TO ORIGINATE LOUDSPEAKER ANNOUNCEMENTS, INCLUDING A BACKGROUND MUSIC OPTION
Electrical and Scientific Apparatus