How many First Alert Wireless Interconnect alarms can be integrated in a system?

First Alert Wireless Interconnect is a complete integrated wireless smoke alarm and carbon monoxide alarm system. As with hardwired units, NFPA states that up to 18 total units can be interconnected (RF or hardwired) with a maximum of 12 of those being smoke alarms and the balance carbon monoxide alarms. Take maximum advantage of the flexibility and protection that a First Alert Wireless Interconnect integrated wireless alarm system can provide.