The first answer devices are commonly used electronic products in most competition, the first answer devices are divided into cable devices and wireless devices. The circuit of the cable calling implements is simple, but it's not convenient to move, and many cable calling implements are fixed in a changeless site such as the television studios, etc. The wireless answer devices are more convenient, for the button of the answers and the receiving parts are separated. They are convenient to move, and can be repeatable used in many kinds of places. At present wireless first answer devices are expensive on the market, generally in thousands of dollars, and a lot of powerful wireless calling implements need to use the computer to achieve its function.

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