The Hybrid RF Module simply plugs into the designated slot in the base of the Hybrid Smoke Alarm. Once fitted with the RF module, the Hybrid Smoke Alarm interconnects with up to 40 alarms on the one network wirelessly via an electronic signal. Interconnected smoke alarms communicate with each other so when one smoke alarm activates all the smoke alarms in the home activate. This gives occupants the best chance of taking action in the event of a fire.