Progressive engineering corporation offers a parallel line privacy adapter, plp-1. By installing this simple adapter on a parallel line, one can ensure that the conversation is not heard on a parallel line. When installed, it automatically disables the parallel line during a telephonic conversation. Parallel line is automatically enabled, when the conversation is over. During incoming call, telephone ring will ring on both the lines and both lines will operate simultaneously. But the parallel line will be disabled automatically when the receiver is picked. When two or more instruments are connected to one telephone line, the universal problem is of keeping privacy of talk. If incoming call is for other person, it will automatically go to that person as soon as the first person puts back the receiver.
