Nowadays you can never be sure anywhere, as there are unlimited varieties of eavesdropping devices on the market. There has been an enormous development in interception technology (please see our catalogue). The new devices do not only use higher frequencies, but also totally different technologies, like GSM and GPS. Furthermore digital tapping devices are rating high meanwhile and everybody knows that it is difficult to locate them. Our PKI 4730 Transition Control Device allows reliable localisation of these devices. Integrated in a frame with interior dimensions of 1 x 2m the Transition Control Device can be arranged before or under every front door. Now you can be sure that your interlocutor will not activate HF-eavesdropping devices without causing an alarm.