The QC000E-840 from IQ is a Zigbee Daughter Card for use with the IQ Panel 4. With the addition of the QC000E-840 to your IQ Panel, the panel can support both Zigbee automation devices and zigbee security devices. If you are upgrading a system that uses Zigbee sensors for their proprietary system, you can use the QC000E-840 and and IQ Panel 4 to replace the main panel but continue to utilize the Zigbee sensors.