Carlo Gavazzi Dupline® Car park system is a complete solution for guiding the drivers directly to the free parking bays. Displays with green arrows and digits are indicating which direction to drive and showing how many parking bays are available in this area. If the area is fully occupied, the display shows red crosses. It is a system of high precision, because each parking bay has an ultrasonic sensor that detects and indicates occupancy. The sensors and displays are linked together via a Dupline® 3-wire.