The PX-2 is a control housed in a metal rack designed to be secured in a traffic control box that you see by the side of the road near traffic control lights. It has relay-logic electronic circuits that control the duration and sequence of light signal events that occur at a pedestrian crossing. There is a black painted metal plate and dials at the front of the unit that permit the adjustment of times dependent upon the size of the intersection at which it is to be installed. There is a large multi-core cable which runs from the unit to a connector.