Amplified voice type of intercommunication equipment comprising interoffice telephone communication apparatus, electrical communication amplifiers, public address systems, telephone apparatus, paging systems, microphones, electric loud speakers and clamps for holding cable signal in position.
Amplified voice type of intercommunication equipment comprising interoffice telephone communication apparatus, electrical communication amplifiers, public address systems, telephone apparatus, paging systems, microphones, electric loud speakers and clamps for holding cable signal in position.
