Simplex 4904-9053 Category : Simplex I accidentally bought this particular unit not realizing I already had one. Oh well, happens.
GE 521BXT Category : GEI think that this smoke detector might be intended for use in security systems.
Notifier F67ODT Category : NotifierF67ODT likely isn’t the model number of the unit as it was just a random number stamped on the wall...
Simplex 4259-25 Category : SimplexThis is a photoelectric smoke detector from the mid to late 1970’s.