ActronAir 4Z-24V Zone Card is an optional 24VAC 4-zone switching module for Classic series residential ducted systems, controlling up to four 24VAC Integrated Zone Barrel Motors via RJ45 connection and including a 20VA plug-in transformer for direct 230VAC supply connection. A failed or missing zone card causes loss of zone switching and airflow distribution across affected zones — fit the 100% Genuine ActronAir 4Z-24V to restore factory zone control. Low voltage inputs only — connecting 240VAC will damage equipment and void your ActronAir warranty.