System Sensor SP101W24M You don’t see many of these alarms that are white. Brand System SensorModel SP101W24MManufacturer System SensorType Alarm (Speaker/Strobe)
Gamewell A8814 Category : GamewellI have no idea what year this alarm is from, only that it’s old and heavy.
GE 521BXT Category : GEI think that this smoke detector might be intended for use in security systems.