Simplex 4903-9101 Clearly, this alarm is not in its prime. Brand SimplexModel 4903-9101Manufacturer UnknownType Alarm (Strobe Plate)
Gentex GXS-4-15/75WR Category : GentexThe previous owner of this alarm “modified” the wire leads coming out of the back.
Simplex 2901-9833 Category : SimplexI have several of these horns because I’ve had several of them unexpectedly break on me.
Grinnell TFX-912P Category : GrinnellJust like the rest of my Grinnell equipment, this smoke detector is from Brigham Young University.