A method, display system, computer software product for controlling an icon appearance are disclosed. The insert has a pin that is disposed to be plugged into the receiving bore and is circumscribed by a second plane surface. The modulation of the temperature gradient is controlled by a surface temperature modulation. The second state corresponds to a second, different mode of fluid communication between the interior of the tubular conduit and the annulus. An ESD discharge current is shunted through the ESD protection circuit and through the ESD clamp during a positive IO ESD event. This can be accomplished, for example, by connecting the on-hookoff-hook button to a switch in the microphone signal line.