ADDA

Speaking tubes; branch boxes [electricity]; telephone receivers; transmitters for the transmission of electronic signals; radios; intercommunication apparatus; radiotelephony sets; telephone apparatus; transmitters (telephone); walkie-talkies; hands-free kits for telephones; acoustic conduits; acoustic membranes used in sound recording or reproducing apparatus; speakers; microphones; sound transmitting apparatus; acoustic couplers; headphones; headsets