What are Radio Frequency (RF) smoke alarms?

Interconnected smoke alarms can be hard-wired, battery-operated, or wireless. Radio Frequency (RF) wireless smoke alarms are increasingly popular as they are easier to install than hard-wired smoke alarms. These interconnected smoke alarms wirelessly connect with each other in a manner similar to pairing your Bluetooth devices, however, they are superior in range and use radio frequency (RF) transmissions. RF wireless smoke alarms can interconnect up to 40 units.