DURÁN co and no₂ gas leak control panel durpark, 1 zone expandable to 4. up to 16 detectors, simultaneous detection of co and no₂ in a loop., 1 zone, expandable to 4 with up to 16 detectors per zone., 3-wire communication. individual supervision of each detector., lcd display, dual ventilation speed and volt-free relay outputs., high accuracy with electrochemical sensors and automatic gas-free calibration.