ActronAir WUK-WH1 WiFi USB Kit adds smartphone app and cloud control to compatible ActronAir Serene wall-hung split systems, plugging directly into the unit's wireless port to link it to your home network. Without it, these systems are limited to handset or local control only. Fit the 100% Genuine ActronAir WUK-WH1 for guaranteed compatibility — confirm your WRE model before ordering.