The telephone set market in Japan was made free, offering users a choice of telephone sets selectable to suit their needs and tastes. This allowed a variety of telephone sets with diversified forms and functions to be released. Among them, the "Response" was a telephone set with an automatic answer function. Telephone sets in the Response series were divided into three types by their answering function: the one which could only send a recorded message, the one which could both send a recorded message and record an incoming message using a single micro-cassette tape, and the one with the same message send/record feature using two standard cassette tapes.

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