Simplex 4904-9137 This is, in fact, a Simplex 4904-9137. It’s just missing its housing. Brand SimplexModel 4904-9137Manufacturer SimplexType Alarm (Strobe)
Simplex 636-820 Category : SimplexThis is the Simplex 4010 user interface which was taken out of a broken 4010.
Simplex 2901-9833 Category : SimplexI have several of these horns because I’ve had several of them unexpectedly break on me.