Simplex 4903-9101 Category : Simplex I believe that this strobe plate was designed for use with a 2901-9838, but it could be used with a variety of different horns. Brand SimplexModel 4903-9101Manufacturer UnknownType Alarm (Strobe Plate)
National Time SG-C4HSZ Category : National TimeThis is a ceiling-mount Gentex Commander 4 Horn/Strobe, which is rebranded by National Time.
Simplex 4903-9219 Category : SimplexThis rectangular Simplex notification appliances has an electromechanical horn mechanism, rather than a speaker or an electromechanical horn mechanism.
