Simplex 4903-9418 Category : Simplex The lack of TrueAlert branding on the front of the alarm, as well as the odd grille, are signs that this is an early version of the TrueAlert. Brand SimplexModel 4903-9481Manufacturer SimplexType Alarm (Speaker/Strobe, 4-Wire)
RSG RMS-1T Category : RSGEither this is an early generation RSG T-Bar or some unique variant of the more common RSG RJRMS-1T-KL.
System Sensor MASS2415ADA Category : System SensorMASS stands for “Multi-Alert Sounder/Strobe.” As the name suggests, it can do more than one tone.
