Video telephones; Manual switching apparatus for telecommunication; Interphones; Automatic switching apparatus for telecommunication; Telephone sets; Telephone transmitters; Telephone receivers; Answering machines; Speaking tubes; Phototelegraphy apparatus; Manual telegraph apparatus; Teletypewriters; Automatic telegraph apparatus; Teletypewriters; Teleprinters; Facsimile machines; Open-wire transmission machines and apparatus; Voice frequency transmission machines and apparatus; Power-line t...